The Amphibians and Reptiles of Michigan: A Quaternary and Recent Faunal Adventure 9780814337134, 0814337139

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J.. Alan Holman

The Amphibians and Reptiles of Michigan

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J. Alan Holman Wayne State University Press Detroit, Michigan

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Great Lakes Books A complete listing of the books in this series can be found online at wsupress.wayne.edu Editors Charles K. Hyde Wayne State University © 2012 by Wayne State University Press, Detroit, Michigan 48201. All rights reserved. No part of this book may be reproduced without formal permission. 16 15 14 13 12 54321 Library of Congress Cataloging-in-Publication Data Holman, J. Alan, 1931– The amphibians and reptiles of Michigan : a Quaternary and Recent faunal adventure / J. Alan Holman. p. cm. — (Great Lakes books) Includes bibliographical references and index. ISBN 978-0-8143-3239-9 (cloth : alk. paper)—ISBN 978-0-8143-3713-4 (e-book) 1. Amphibians—Michigan. 2. Reptiles—Michigan. 3. Amphibians, Fossil—Michigan. 4. Reptiles, Fossil—Michigan. I. Title. L653.M5H65 2012 597.809774—dc23 2011031524

Designed by Brad Norr Design Typeset by Brad Norr Design Composed in Centaur Printed in China

Dedicated to Michigan teachers of herpetology, past and present

Once in a blue moon a snake hurts somebody, or the fishing lags, or the frogs wake up the baby; but on the whole our exotherms are a blessing— one of the real, marketable assets of the state and one deeply involved in our appeal to visitors from the outside. Archie Carr and Coleman J. Goin (1955)

Author’s Note: The gentlemen who are the source of this epigraph were referring to Florida, but what they said could apply as well to Michigan, where the salamanders, frogs, turtles, and snakes of the state are as dear to the hearts and minds of some as salmon, turkey, and deer are to others.

Publisher’s Note Wayne State University Press expresses its gratitude to James Harding for his work to bring this book to completion following the untimely death of Alan Holman. Holman died suddenly just days after turning in his manuscript to the press, leaving his manuscript finished but not perfected. Harding, together with

colleagues James Gillingham and David Mifsud, provided some additional photographs and reviewed the copyedited manuscript and page proof, updating references and other information as necessary. Without the generous help of Holman’s friends, the press would have been challenged to continue the publication.

Contents Preface . ............................................................................................................................................. xv Acknowledgments . ........................................................................................................................... xvii A Note on the Species Range Maps ................................................................................................... xix Part 1. Introduction: Michigan as a Herpetological Habitat ................................................................. 1 Part 2. Species Accounts . .................................................................................................................. 27 Class Amphibia ................................................................................................................................... 29 Order Caudata (Salamanders) ...................................................................................................... 30 Family Ambystomatidae Blue-spotted Salamander ........................................................................................ 31 Blue-spotted/Jefferson Salamander Complex . ........................................................ 34 Spotted Salamander . ............................................................................................... 36 Marbled Salamander ...................................................................................... 40 Small-mouthed Salamander . ................................................................................... 43 Eastern Tiger Salamander . ...................................................................................... 46 Family Plethodontidae Four-toed Salamander ............................................................................................. 52 Eastern Red-backed Salamander ............................................................................ 54 Family Proteidae Common Mudpuppy .................................................................................................. 58 Family Salamandridae Eastern Newt ............................................................................................................ 62 Family Sirenidae Western Lesser Siren ............................................................................................... 65 Order Anura (Frogs and Toads). .................................................................................................... 67 Toads . ..............................................................................................................................................67 Family Bufonidae Eastern American Toad............................................................................................. 68 Fowler’s Toad............................................................................................................ 72

The Amphibians and Reptiles of Michigan

Frogs ............................................................................................................................................. 75 Family Hylidae Blanchard’s Cricket Frog ....................................................................................... 75 Cope’s Gray Treefrog .............................................................................................. 77 Gray Treefrog .......................................................................................................... 78 Northern Spring Peeper ......................................................................................... 81 Boreal Chorus Frog ................................................................................................ 84 Western Chorus Frog .............................................................................................. 84 Family Ranidae American Bullfrog ................................................................................................... 87 Northern Green Frog ............................................................................................... 90 Pickerel Frog .......................................................................................................... 93 Northern Leopard Frog ........................................................................................... 95 Mink Frog ................................................................................................................ 99 Wood Frog ............................................................................................................ 101 Class Reptilia .................................................................................................................................. 104 Order Testudines (Turtles) ......................................................................................................... 104 Family Chelydridae Eastern Snapping Turtle ........................................................................................ 105 Family Emydidae Painted Turtle ....................................................................................................... 111 Spotted Turtle ....................................................................................................... 117 Blanding’s Turtle ................................................................................................... 121 Wood Turtle ........................................................................................................... 125 Northern Map Turtle .............................................................................................. 131 Eastern Box Turtle ................................................................................................ 135 Red-eared Slider .................................................................................................. 140 Family Kinosternidae Eastern Musk Turtle .............................................................................................. 143 Family Trionychidae Eastern Spiny Softshell ......................................................................................... 147 Order Squamata ......................................................................................................................... 149 Lizards ....................................................................................................................................... 150 Family Scincidae Five-lined Skink ..................................................................................................... 150 Family Teiidae Six-lined Racerunner............................................................................................. 153

x

Contents

Snakes ....................................................................................................................................... 155 Family Colubridae Kirtland’s Snake. .................................................................................................... 155 Blue Racer. ............................................................................................................ 158 Northern Ring-necked Snake................................................................................. 162 Eastern Hog-nosed Snake...................................................................................... 165 Eastern Milksnake.................................................................................................. 168 Copper-bellied Watersnake. .................................................................................. 171 Common Watersnake............................................................................................. 174 Smooth Greensnake............................................................................................... 177 Central Ratsnake. .................................................................................................. 180 Eastern Foxsnake................................................................................................... 183 Western Foxsnake.................................................................................................. 186 Queen Snake. ......................................................................................................... 188 DeKay’s Brownsnake.............................................................................................. 191 Northern Red-bellied Snake................................................................................... 194 Butler’s Gartersnake.............................................................................................. 197 Northern Ribbonsnake. .......................................................................................... 199 Eastern Gartersnake.............................................................................................. 201 Family Viperidae Eastern Massasauga. ............................................................................................. 205 Part 3. Quaternary Remains of Michigan Amphibians and Reptiles................................................. 211 Michigan’s Pleistocene Herpetofauna. ............................................................................................ 215 Anurans. ..................................................................................................................................... 215 Family Bufonidae American Toad. ...................................................................................................... 216 Family Ranidae Green Frog. ............................................................................................................ 216 Turtles........................................................................................................................................... 216 Family Emydidae Painted Turtle......................................................................................................... 217 Family Trionychidae Spiny Softshell Turtle. ............................................................................................ 218 Michigan’s Holocene Herpetofauna. ................................................................................................ 219 Anurans. ..................................................................................................................................... 219 Family Bufonidae American Toad. ...................................................................................................... 219 Family Hylidae Spring Peeper. ....................................................................................................... 219

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The Amphibians and Reptiles of Michigan

Reptiles ........................................................................................................................................ 220 Family Chelydridae Eastern Snapping Turtle ........................................................................................ 220 Family Emydidae Painted Turtle ....................................................................................................... 220 Spotted Turtle ......................................................................................................... 221 Blanding’s Turtle ..................................................................................................... 221 Specifically Undetermined Map Turtle ................................................................... 222 Family Kinosternidae Eastern Musk Turtle ................................................................................................ 222 Family Trionychidae Spiny Softshell ........................................................................................................ 222 Herpetofauna of Michigan Archaeological Sites ............................................................................... 222 Anurans ........................................................................................................................................ 223 Family Bufonidae American Toad ........................................................................................................ 223 Toad ........................................................................................................................ 224 Family Ranidae American Bullfrog .................................................................................................. 224 True Frog ................................................................................................................ 224 Reptiles ........................................................................................................................................ 225 Family Chelydridae Snapping Turtle ....................................................................................................... 225 Family Emydidae Painted Turtle ......................................................................................................... 227 Spotted Turtle ......................................................................................................... 229 Blanding’s Turtle ..................................................................................................... 229 Wood Turtle ............................................................................................................. 231 Northern Map Turtle ............................................................................................... 231 Eastern Box Turtle .................................................................................................. 232 Pond Slider ............................................................................................................. 233 Family Kinosternidae Eastern Musk Turtle ................................................................................................ 233 Family Trionychidae Spiny Softshell ........................................................................................................ 233

xii

Contents

Family Colubridae North American Watersnakes ................................................................................. 235 Eastern Foxsnake . .................................................................................................. 235 North American Gartersnakes ................................................................................ 235 The Pleistocene ................................................................................................................................. 236 References . ....................................................................................................................................... 253 General Index . ................................................................................................................................... 277 Taxonomic Index ................................................................................................................................ 285 Site Index ........................................................................................................................................... 289

xiii

Preface

M

ichigan, an ecologically transitional border state with Canada, is blessed with seventysix natural communities (Michigan Natural Features Inventory 2007) that together support a diverse assemblage of animals and plants, including fifty-four species of amphibians and reptiles. Because Michigan consists of two peninsulas that project into large freshwater seas and because it was completely covered by a massive ice sheet a relatively short time ago, scientists, students, and other enthusiasts have many questions about the dispersal and biology of the Michigan herpetofauna—the amphibians and reptiles. For example, eight out of seventeen papers once presented at the zoology section of an annual meeting of the Michigan Academy of Science, Arts, and Letters were about Michigan amphibians or reptiles. All is not happy banter when Michigan herpetologists get together, as we all fidget and fret about the diminishing populations of amphibians and reptiles in the state. The most frightening thing is that not only are the officially threatened and endangered species of concern but also the many species that were very common throughout large portions of the state as recently as the early 1980s. They too are becoming rare and exist only as fragmented populations. That said, it is surprising that Michigan does not have a post–World War II detailed monograph on the amphibians and reptiles of the state (a “state herpetology”) like those of other states in the region—for example, The Natural History of Reptiles of Wisconsin (Vogt 1981), The Amphibians and Reptiles of Illinois (P. W. Smith 1961), Amphibians and Reptiles of Indiana (Minton 2001), and The Reptiles of Ohio (Conant 1951). The latest work of this kind on Michigan alone was assembled in 1928 and covered forty-four of the fifty-four species presently known in the state (Ruthven et al. 1928).

This book is intended not only to rectify this situation but to go a step further than any available “state herpetology” in the United States by including detailed Quaternary (Pleistocene and Holocene) accounts that include both “natural” and archaeological site records. Thus, this analysis of the Michigan herpetofauna uniquely bridges the gap between neo- and paleoherpetology. It emphasizes that modern herpetofaunas are a reflection of Pleistocene and Holocene events and that this is especially true in Michigan, where the entire modern assemblage was forced to reinvade the area after the last withdrawal of the ice. Part 1 starts with a discussion of Michigan as an amphibian and reptile habitat. This section begins with an account of the geological history of Michigan, covering basic bedrock geology and Pleistocene glacial history. Next, Michigan’s climatic and vegetational history are discussed. Various Michigan regional divisions are detailed with attention to biotic provinces, vertebrate paleontological regions, and Michigan regional landscape ecosystems. Next, characteristic recent amphibian and reptile habitats in the state are described, including forest, grassland, lake and pond, bog and swamp, and river and stream. A special section looks at urban habitats. Following this is a discussion of the history of early and modern herpetological studies in Michigan, including institutions related to the protection, study, and maintenance of amphibians and reptiles in the state. Finally, procedures used in the identification of both modern and fossil amphibians are explained. The heart of the book, part 2, consists of recent species accounts. In these recent accounts, Michigan’s fifty-four amphibian and reptile species are presented with their scientific and common names, identification, general distribution, Michigan distribution (with a range map), geographic variation, habitat and habits,

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The Amphibians and Reptiles of Michigan

reproduction and growth, diet, predation and defense, interaction with humans, behavioral characteristics, population health, and general remarks. Part 3 is a discussion and summary of the Michigan herpetofauna in Quaternary and recent historical times. Topics include a reexamination of the Pleistocene in Michigan and the amazing survival of amphibians and reptiles during these stressful times, patterns of herpetological reoccupation of postglacial Michigan by amphibians and reptiles, and finally a summary of Michigan amphibians and reptiles in the Holocene (including archaeological sites) and modern times. In this part, the species accounts include Pleistocene, Holocene, and archaeological records. Accounts of Michigan amphibian and reptile species of the two epochs include the sites, material, and remarks. Accounts related to

xvi

archaeological finds include sites, chronological age, and remarks. This collection of information should be heartily welcomed by herpetologists, especially those in North America and the Midwest. The book should also be of great interest to vertebrate paleontologists, zoologists, ecologists, and general biologists. Finally, I’m certain the book will be embraced by anyone who loves salamanders, frogs, turtles, and snakes. I have tried to write with as little scientific jargon as possible. But, when jargon has slithered into my writing, please forgive me for it. I have included some whimsical accounts of my experiences in the field and laboratory with both fossil and modern amphibians and reptiles, as well as a wee bit of levity now and then.

Acknowledgments

I

gratefully acknowledge those special individuals who have shared their interest in Michigan amphibians and reptiles with me. This book could not have been written without them. These people are Laura Abraczinskas, Kenneth Andrews, James Ball, Gary Casper, the late Roger Conant, Justin Congdon, Michele Costibile, Carl Doney, John Douglass, Carl Ernst, James Farlow, Lesley Fay, Bill Flanagan, James Fowler, Whitfield

Gibbons, James Gillingham, the late Dirk Gringhuis, Lisa Hallock, James Harding, the late Max Hensley, Paula Hildebrandt, Arnold Kluge, Yu Man Lee, Barbara Lundrigan, David A. Mifsud, Peter Ocello, the late Sherman Minton, Dean Premo, Karel Rogers, John Rowe, Lori Sargent, Greg Schneider, the late Phillip Smith, Craig Weatherby, Peter Wilson, and the late Vincent Wilson.

xvii

A Note on the Species Range Maps

S

ince 1991 I have endeavored to document the distribution of the species of amphibians and reptiles in Michigan by checking as many literature and museum records as possible (see Holman 2004) as well as records documented by herpetologists presently active in Michigan. James H. Harding of the Michigan State University Museum, Lori G. Sargent of the Michigan Department of Natural Resources (MDNR), and David A. Mifsud, Herpetological Resource and Management, LLC (HRM), were especially helpful in providing new records from their ongoing projects. The University of Michigan Museum of Zoology online program about the distribution of amphibians and reptiles in Michigan produced by Greg Schneider and Arnold Kluge was very helpful. Other recent providers of Michigan herpetological records include Kenneth Andrews, James Ball, James Gillingham, and John Douglass. Much work remains to be done to fully document the presence or absence of amphibians and reptiles in Michigan. Fortunately, a Michigan Herp Atlas Project

has been under way in Michigan since 2002. This atlas is supported by the Nongame Fish and Wildlife Trust Fund and the State Wildlife Grants program. For more information or a copy of the Herp Atlas manual and data cards, visit the MDNR website at www.michigan. gov/dnr. The maps indicate county occurrences for each species rather than using small dots to indicate exact localities (e.g., as in Minton 2001). Michigan’s herpetofauna has already been targeted by illegal collectors in the pet trade (J. H. Harding, pers. comm.), and such dots on state maps can be used by these individuals to find local herpetological “hot spots.” In this book, the recorded presence of a herp species in a county (or on an island) is indicated by a large closed circle within the county or adjacent to an island. Only three major islands are included in the range maps, but the documented presence of herp species on other Michigan islands may be found within the individual species accounts.

xix

The Amphibians and Reptiles of Michigan

1

Introduction Michigan as a Herpetological Habitat

M

ichigan is a geographically unique state, consisting of two large peninsulas that penetrate large inland freshwater seas separated from each other by only a few miles of water (see fig. 1). The physical and biological conditions of the two peninsulas differ enough to affect the composition of the fauna and flora of the two areas, yet the herpetofauna of the Upper Peninsula (UP) shares many species with both the northern Lower Peninsula and contiguous northern Wisconsin.

FIG. 2. Geologic time scale. Illustration by Teresa Petersen.

Bedrock and the Great Lakes

FIG. 1. Michigan, showing its counties and (1) Beaver, (2) Bois Blanc, and (3) Drummond Islands. Illustration by the author.

Geological History Understanding at least some of the geological history of Michigan is essential to understanding the distribution of herpetological species and their habitats in the state. The first thing to consider is the topography of Michigan, which is a product of both the underlying bedrock and the drastic effects of glaciation over the last two million years.

Over much of its surface, Michigan is a mass of unconsolidated Pleistocene (“Ice Age”) sediments, thousands of years old and ranging from about twentyfive to more than one hundred feet thick. These Pleistocene sediments consist mainly of boulders, cobbles, pebbles, sand, silt, and clay. They lie upon consolidated layers of ancient bedrock many million to more than a billion years old and thousands of feet thick. Michigan bedrock (see fig. 3) consists of many types of rocks representing the three main rock divisions: igneous, sedimentary, and metamorphic (see table 1). Common Michigan igneous rocks include ash, basalt, felsite, gabbro, granite, and obsidian. Familiar Michigan sedimentary rocks include sandstone, shale, siltstone, chert, flint, coal, gypsum, dolomite, limestone, and salt. Michigan metamorphic rocks include gneiss, marble, phyllite, schist, slate, and quartzite.

1

The Amphibians and Reptiles of Michigan

Unlike the situation in unglaciated southern Indiana and Ohio, outcrops of bedrock are rare in Lower Michigan and are mainly confined to road cuts and a few river and stream valleys. Some outcrops of bedrock occur in the eastern UP, especially in road cuts, and granitic outcrops are not rare in the western UP (see Dorr and Eschman 1970; Holman 1995a; Holman and Holman 2003).

Table 1. Common Michigan Rocks Igneous

Sedimentary

Metamorphic

Ash

Clastics: Boulders, cobbles, pebbles

Gneiss

Basalt

Sand and sandstone

Marble

Felsite

Silt and siltstone

Phyllite

Gabbro

Clay and shale

Schist

Granite

Chemical and Biological:

Slate

Chert and flint Coal Gypsum Dolomite Limestone Salt Obsidian

FIG. 3. Distribution of bedrock in Michigan: PC, Precambrian; C, Cambrian; O, Ordovician; S, Silurian; and D, Devonian. Illustration by the author, from Holman and Holman (2003), courtesy of the University of Michigan Press.

What does this mean to the herpetologist? The flaky or layered bedrock shales found in the meandering streambeds of unglaciated southern Indiana and Ohio are rare in Michigan. Here the streambeds consist of glacially derived boulders, cobbles, pebbles, sand, silt, and clay—a discomforting situation for people used to peering under flaky or layered shales for salamanders and small snakes. Moreover, the bedrock ledges, commonly found in the hillsides of southern Indiana and Ohio, occur in relatively few places in Michigan. When these ledges occur in southern Michigan, it is mainly where erosion has exposed bedrock in river valleys, such as has occurred in the Grand Ledge area west of Lansing. In the UP, occasional fissures and rock shelters harbor small amphibians (e.g., Holman et al. 2003) and perhaps

2

Quartzite

reptiles. The rocky ledges, fissures, and rock shelters in the unglaciated regions in states south of Michigan provide not only temporary shelters for amphibians and reptiles but hibernating sites for several large species of snakes. But compared to states to the south, there is not much exposed bedrock under which Michigan herps might hide. The Great Lakes we know today are the products of relatively recent glacial ice, sedimentary debris, and meltwater acting on bedrock produced hundreds of millions of years ago during the Paleozoic era (see fig. 3). Before the Pleistocene, the basins that hold the present Great Lakes were stream valleys in the bedrock as well as products eroded from the bedrock in ancient times. When the ice sheets advanced, they tended to move along these valleys, following the path of the least resistant rocks. Ultimately, water from melting ice filled the gouged-out basins to form the Great Lakes. The present Great Lakes all drain in an easterly direction. Lake Superior drains into Lake Huron at Sault Ste. Marie, Lake Michigan into Lake Huron through the Straits of Mackinac; Lake Huron drains south along the St. Clair River into Lake Erie, and Lake Erie drains into Lake Ontario, which drains into the Atlantic Ocean by way of the St. Lawrence River. Lake Superior is the coldest and deepest, and Erie is the warmest and shallowest of the present lakes. The big lakes began to fill up in earnest as the latest great ice sheet began to melt, sometime before 13,300 years ago (13.3 ka BP). (The abbreviation represents

1. Introduction: Michigan as a Herpetological Habitat

“kilo annum before present,” or a thousand years before present.) The so-called Nipissing stage of the formation of the lakes occurred about 4 ka BP when the Great Lakes were nearly in their present stage of development. Between these times, glacial advances and retreats caused the shorelines to fluctuate and the lakes to take on various different shapes. The Great Lakes now occupy 95,000 square miles of the earth’s surface and are such large features that they can easily be seen from the moon. Michigan contacts more of these lakes (Superior, Michigan, Huron, and Erie) than any other state. The Great Lakes and their outliers and tributaries not only provide abundant habitats for Michigan amphibians and reptiles but they also greatly modify the climate of the two peninsulas.

The Pleistocene Ice Age in Michigan The Pleistocene is popularly called the Ice Age, although it is really the latest of many cold periods dating back to about the Precambrian (see fig. 2). The Pleistocene began about 1.8 million years ago (1.8 Ma BP) and ended about 10 ka BP, with the worldwide extinction of many large to giant-sized mammals. (Similar to “ka BP,” the first abbreviation in the previous sentence represents “mega annum before present,” or a million years before present.) These mammals include the elephant-like mastodonts and mammoths that were very common in Michigan from about 12 ka BP to 10 ka BP, when they suddenly became extinct. Actually, Michigan is a

microcosm for the study of the “why” of the sudden extinction of these giant mammals. It is also a microcosm for the study of the reoccupation of the state by plants and animals (including amphibians and reptiles), which occurred after the withdrawal of the last Pleistocene ice sheet, a mass that entirely blanketed Michigan and all but the southern parts of Illinois, Indiana, and Ohio (see fig. 4). Time intervals associated with general ice sheet advances are called “glacial ages,” while those associated with general glacial retreats are called “interglacial ages.” Only one glacial age is well documented in Michigan and that is the latest one, called the Wisconsinan. The other so-called classical glacial ages are named and commented on in table 2. The Wisconsinan is generally thought to have begun about 110 ka BP and to have ended at the end of the Pleistocene, 10 ka BP. The Holocene epoch has lasted from 10 ka BP to the present. Table 2. Classical names for North American glacial and interglacial ages, with comments Wisconsinan Glacial Lasted from about 110 ka BP to 10 ka BP, the end of the Ice Age Sangamonian Interglacial Thought to have lasted from about 150 ka BP to 110 ka BP, but the chronology is somewhat questionable Illinoian Glacial Chronology not fully documented but still widely used Yarmouthian Interglacial Term obsolete Kansan Glacial Chronology not fully documented but still used Aftonian Interglacial Term obsolete Nebraskan Glacial Sites previously assigned to Nebraskan now considered to be Pliocene

Fig. 4. Maximum extent of the Illinoian and Wisconsinan ice sheets in the Great Lakes region. The lines represent the farthest south the blanket of ice penetrated in North America during the Pleistocene. Illustration by the author.

Actually, several warmer periods within the generally cold Wisconsinan led to the temporary withdrawal of the ice sheet. These warmer periods are called “interstadials,” and where they are well documented, they have been given names. Two interstadials, originally named in the Toronto, Ontario, region in Canada, have also been identified in Michigan. These are the Port Talbot interstadial, which is estimated to have existed between about 54 ka BP to 45 ka BP, and the Plum Point interstadial, which existed from about 34 ka BP to 23 ka BP. No amphibians or reptiles are known from either interstadial in Michigan. Moreover, the only Michigan vertebrates known from the Wisconsinan interstadials are

3

The Amphibians and Reptiles of Michigan

a lesser scaup (a diving duck) and a mammoth from the Plum Point (Holman 2001b). The dynamic activity of glaciers changes the landscape in several ways (see fig. 5). Mainly it erodes the land that it moves over and carries rocks and debris it has plucked from the surface of the land and dumps this material either directly, by melting in place, or by meltwater systems that spread the material over the countryside. Most of the material carried by the ice is held in suspension near the bottom of the ice. The Pleistocene ice sheets were so thick that there appears to have been no limit to the size of objects that they could transport. In western Canada, giant pieces of glacial “real estate” called “megablocks” that were more than a mile wide and hundreds of feet thick were carried for up to two hundred miles by the ice.

FIG. 5. A sketch of the withdrawal of the last ice sheet in Michigan at the end of the Pleistocene. The sun comes up in the east to shine on the leading edge of the huge glacier, which is seen as a sheer cliff. Glacial meltwater floods the newly exposed land in various patterns as streams erode the top of the ice. Illustration by the author, from Holman and Holman (2003), courtesy of the University of Michigan Press.

Some of the objects carried by the Pleistocene ice and deposited over the Michigan countryside, such as boulders and cobbles flattened by water wear, may be used by amphibians and reptiles for shelter, but these are not as desirable for this purpose as the flatter shales and other friable (easily crumbled) rocks that occur in the unglaciated areas of the states to the south. Sand and mixtures of sand and silt, carried and deposited by glacial processes, have provided soils conducive to nest digging by turtles and burrowing by certain sand-loving species such as toads and Eastern Hog-nosed Snakes.

4

Ice sheet sediments are commonly called “till” or “outwash deposits.” Till comes directly from the ice and consists of mixed particles of all sizes and shapes. Till forms structures known as “moraines.” Most of the big hills in Michigan are derived from so-called end moraines that formed at the end of various ice lobes. These glacially derived hills modify the climate and undoubtedly have an important role in the distribution of herpetological species in the state. Large areas on both peninsulas of Michigan have additional glacial features called “drumlins,” “eskers,” and “kames” that can usually be easily identified from a car window (see Holman and Holman 2003). Drumlins are elliptical hills composed of glacial till left behind when the glacier melted. The direction of the ice flow is indicated by the direction of the long axis of drumlins. Eskers are narrow, snakelike ridges of sediments laid down in tunnels in or under retreating ice. Esker fields winding around the countryside provide a variable topography that often forms excellent habitat for amphibians and reptiles. Kames, isolated rounded hills of glacial outwash sand and gravel, may have less impact on herp distribution than eskers and drumlins. Nevertheless, snakes, moving from lowlands to highlands to find rodent prey after emerging from hibernation, sometimes ascend these hills. Glacial “kettle holes” are rounded depressions created from rounded blocks of ice that melted after the ice withdrew. Some large kettle holes form natural ponds and lakes in Michigan and offer habitat to many species of aquatic and semiaquatic amphibians and reptiles. Other kettle holes have filled in and been replaced by willow-sedge communities (incidently, a good place to probe for mastodont or mammoth bones; see Holman 2001a). Speaking in the broad sense, Michigan is fortunate to possess ancient lake plain and glacial surface formations (see fig. 6) that can be classified as highlands, hilly uplands, upland and lowland plains, and lake-border plains. These landforms produce a complex of features that even a short drive through Michigan will reveal. Features with elevations well over a thousand feet above sea level are fairly common in the northern part of the Lower Peninsula; the highest lands in the Upper Peninsula reach approximately 1,800 feet. The largest areas of lake plains are found in the eastern part of the

1. Introduction: Michigan as a Herpetological Habitat

UP, the area around Saginaw Bay west to Midland, and in extreme southeastern Michigan. These areas are (or were) usually associated with extensive marshes, which are important habitats for many species of amphibians and reptiles.

Fig. 6. Generalized surface formations in Michigan. The shaded areas indicate ancient lake plains; unshaded areas indicate glacial surface formations such as moraines, till plains, and outwash plains. Illustration by the author, from Holman and Holman (2003), courtesy of the University of Michigan Press.

Pleistocene and Holocene Climatic and Vegetational History In Michigan, Pleistocene and Holocene climatic and vegetational changes were dramatic and obviously greatly affected the distribution and abundance of amphibians and reptiles over time.

Pleistocene Changes The patterns of reestablishment of plant communities in previously glaciated regions in Michigan are very important, as they relate to the recolonization patterns of animals, including amphibians and reptiles. Wisconsinan postglacial events have been relatively well studied in Michigan (Kapp 1999). When the Wisconsinan ice sheet retreated, it left a mainly sterile blanket of gravel, sand, and mud (Holman 2001a). Therefore, the establishment of stable plant communities in these areas must have taken considerable time. During a temporary withdrawal of the ice about 40 ka BP during the Cherry Tree substage in Kalkaska County, and again about 24 ka BP during the Plum Point

substage in Muskegon County, a boreal or subboreal climate was indicated by paleobotanical studies. The open forests were dominated by spruce and pine, and tamarack and cedar were prominent in the swamps. Sedges and cattails occurred in the marshy areas. Herbaceous plants indicative of disturbed ground were found in better-drained situations. About 14.8 ka BP, during the period when the ice sheet began its final withdrawal, the plant fossil record in southern Michigan indicates evidence of marshes and muskegs in the lowlands. By about 13 ka BP it is estimated that almost half of the Lower Peninsula was free of ice. At this time, most of the well-drained habitats contained scattered stands of pioneer trees such as juniper, aspen, ash, and spruce. Sun-tolerant shrubs such as crowberry, silverberry, and willow were also present in this setting. Nevertheless, whether this landscape was essentially a treeless tundra or an open forest of spruce, tamarack, and mixed deciduous trees is not known. Again, in southern Michigan, from about 12.5 ka BP to about 11.8 ka BP, a boreal forest dominated by spruce was present, but there were also other areas of boreal parkland and open woodland. In the northern part of this area, boreal parkland dominated, and tundra vegetation occurred in open situations along the ice front and on exposed slopes and hills. Marked changes in the pollen record occurred between 11.8 and 9.9 ka BP. About 10.6 ka BP, jack pine and red pine began to replace spruce in southwestern Lower Michigan. By 10 ka BP white pine made its appearance, and hardwood trees such as birch, blue beech, and elm became abundant. R. O. Kapp (1999, 51) suggested that “the paleoecological changes that occurred between 10,500 and 9,500 BP were of such revolutionary proportions that these are the primary basis for defining the boundary between late-glacial and the postglacial or Holocene.” His observation generally concurs with the 10 ka BP date that is accepted by vertebrate paleontologists as the end of the Pleistocene (e.g., Holman 2001a; Meltzer and Mead 1983).

Holocene Changes The Holocene began about 10 ka BP and was marked by the absence of many large mammal species that became extinct at the end of the Pleistocene (Holman 2001a;

5

The Amphibians and Reptiles of Michigan

Meltzer and Mead 1983). The absence of these large mammals, especially the elephant-sized mastodonts and mammoths that were the ecologically dominant giant herbivores (called “megaherbivores”) of the community, vastly changed the ecological balance in North America. African elephants and rhinos have been referred to as modern ecological analogs to mastodonts and mammoths. When elephants and rhinos are lost to the community in Africa, a domino effect leads to the disruption and often the extirpation of much of the community (Wier 1972). African elephants, for instance, keep the scrub vegetation trimmed down to such an extent that grasses are available for several species of grazing ungulates. When elephants are removed, the scrub grows back, and grasses are not available for these other important members of the community. Surely the composition of the vegetation in Michigan must have changed dramatically when mastodonts and mammoths suddenly became extinct at the end of the Pleistocene. Turning to the very early Holocene, more than twenty paleoecological studies that used a variety of

FIG. 7. Vegetation of Michigan 9,900 years ago: MF, mixed conifer and northern hardwood forest; PH, pine-dominated forest with hardwoods; PSH, pine-spruce-hardwood forest; S, spruce forest; SP, spruce-pine forest; T, tundra; marsh symbol, swamp forests, marshes, and wetlands. From Halsey and Stafford (1999), courtesy of the Cranbrook Institute of Science.

6

“modern techniques” provided data for a general vegetation map for the Michigan area at 9.9 ka BP (Kapp 1999). At this time mixed forests—mainly mesophytic hardwoods with some white pine—occurred across most of the region now occupied by the lowest two tiers of counties, with swamp forests and marshes occurring in what is now extreme southeastern Michigan (see fig. 7). North of these lower counties and up to a line at about the top of the “thumb” (for readers not familiar with the state, the shape of the Lower Peninsula is often compared to a mitten, with the thumb on the eastern side), mixtures of pine-spruce-hardwood forests, pine-dominated forests with hardwoods, and spruce-pine forests (confined to the thumb) occurred. Near the Saginaw Bay–Midland area, swamp forests with marshes and wetlands were found. The upper part of the Lower Peninsula and the Beaver Archipelago consisted of spruce-pine forests (Kapp 1999, 50, map). In the UP, the final Marquette advance of the Lake Superior ice lobe covered approximately the upper third of the peninsula (see fig. 7). About the eastern third of the ice-free area in the UP consisted of spruce forest. The southern-extending central part had pine-dominated forest with hardwoods, and about the western third had spruce-pine forest. Possibly, tundra occurred near the base of the northward-extending Keweenaw Peninsula. The amphibians and reptiles moving back into these Michigan vegetational associations around 9.9 ka BP are classified mainly in the “primary reinvader” category, a topic that is discussed in detail later in the book. In the Early and Middle Holocene, significant expansion of forest species into Michigan occurred. Black and white spruce as well as jack and red pine extended rapidly into Michigan following the retreat of the ice. White pine reached the thumb by 9.4 ka BP, the central part of the Lower Peninsula by 9 ka BP, and the eastern part of the UP by 8.3 ka BP. Hemlock reached Beaver and North Manitou Islands by about 7 ka BP and then spread both northward and southward, reaching central Lower Michigan by 5 ka BP and the northwestern part of the UP by 4.2 ka BP (Kapp 1999). Spreading westward from what is now Ontario, American beech occurred in Lapeer County, Michigan, by 8 ka BP and across the southern part of the Lower Peninsula between 7.6 and 4.2 ka BP. Relative to the postglacial climate in Michigan, there appears to have been a general and

1. Introduction: Michigan as a Herpetological Habitat

long-term increase in temperature extending from 9 to at least 2.5 ka BP with the driest and warmest period of the Holocene across Michigan originally being dated from 4.5 to 3.5 ka BP (Kapp 1999). Modern calibrations indicate the latter interval actually occurred about 5.5 to 4.5 ka BP. Conflicting pollen dates in various parts of the country as well as in different parts of Michigan make it somewhat difficult to define the exact length of this warm, dry, so-called Hypsithermal Interval in the state. This long warming trend is very important relative to the possible patterns of the postglacial reoccupation of Michigan by amphibians and reptiles, a subject that is also discussed later. A Late Holocene cooling period, known as the Little Ice Age, is very important in the consideration of the withdrawal of herpetological species from Michigan as well as possible relict populations left behind. In the European Alps, historical records show that the Little Ice Age was composed of several episodes of glacial advances and retreats, and climatic effects resulted in crop failures and famines (Matsch 1976). In fact, farms built near the glacial margin were destroyed by an ice advance in the 1700s. Attempting to define the extent of the Little Ice Age in Michigan, Kapp (1999) noted that the most detailed paleoecological study covering the last 1,500 years in Michigan was that of Bernabo (1981), who examined pollen and other data along a NW-SE transect from Charlevoix County to Crawford County in northern Lower Michigan. In this statistical analysis, modern pollen and climatic data were compared with pollen data from sediment cores taken at four lakes. Bernabo suggested that a prolonged cooling period began 1.2 ka BP and that the cooling reached a peak (1ºC below a 1931–60 mean) by the 1700s. He suggested a warming of 0.5ºC occurred from AD 1750 to 1850.

Recent Vegetational Changes Before European settlement, Michigan vegetation consisted mainly of forest. Broadleaf species were dominant in southern Lower Michigan; American beech, sugar maple, and other hardwoods occurred on the richer upland soils, and oak-hickory associations occurred on the more sandy soils. In northern Lower Michigan and the eastern part of the Upper Peninsula, beech, maple, yellow birch, hemlock, and balsam fir were dominant in

upland areas, especially those that occurred near Lake Michigan. The sandy soils of the interior parts of this region supported large areas of pine, and the low, boggy areas produced black spruce–white cedar associations. In the western part of the UP, bogs were relatively uncommon. The rocky landscape there supported communities composed of sugar maple, basswood, red oak, yellow birch, and hemlock, but beech was absent. From about 1850 to its peak in 1882 (Dickmann and Leefers 2003), exploitive logging occurred in the pine lands of Michigan. Coincident with and following this logging, catastrophic fires ravaged Michigan vegetation. One fire in October 1871 burned more than a fourth of the total acreage of the Lower Peninsula of Michigan (see Dickmann and Leefers 2003, 156, fig. 7.5) as well as a considerable area in Menominee and Delta counties adjacent to Green Bay in the UP. Following the logging days, attempts to cultivate areas of former forests in northern Michigan further changed the composition of the vegetation. Presently, stands of beech and maple on the better upland soils resemble their presettlement counterparts. But pine forests that occur on poorer soils recover more slowly from exploitation and have been variously replaced by stands of jack pine, white birch, or aspen. In southern Lower Michigan, most of the better soil that was formerly forested is presently under cultivation. Relative to wetland communities, the Michigan Natural Features Inventory (MNFI), established in 1980, named twenty-seven palustrine (wet or marshy habitats) and two “palustrine/terrestrial” areas for a total of twenty-nine wet or sometimes wet situations. The definitions of these communities are complex. However, such precisely defined communities can be monitored in the future for vegetational change and can provide interesting information on which to base conservation and management decisions. Nevertheless, there is no doubt that Michigan’s wetland habitats have been drastically reduced or degraded since European settlement by urban development and sprawl, cultivation, ditching and draining, the application of chemical and natural fertilizers, and the dumping of industrial wastes. These factors have also degraded many of Michigan’s lakes, rivers, and streams, though regulatory efforts have effected some improvements in water quality in recent decades.

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The Amphibians and Reptiles of Michigan

Amphibian and reptile habitats have obviously been affected by all these past and recent changes. Some herpetological species have adapted well to some changes, but others are on the brink of extinction because of them. I find the most disturbing recent trend is that many formerly common and widespread amphibian and reptile species appear to be declining or are becoming rare, even in some of the protected natural habitats in the state.

Broad Regional Divisions in Michigan Michigan has been divided into several broad regional divisions, all of which reflect biological communities in one way or another, but each of which is based on somewhat different criteria. Three are important to consider here: biotic provinces, the Mason-Quimby Line, and the Regional Landscape Ecosystems of Michigan. What I find especially interesting is that all three of these systems divide the Lower Peninsula of Michigan into upper and lower units at about the same latitude.

Biotic Provinces The biotic provinces concept grew out of the study of regional faunal assemblages in North America. This concept is usually associated with L. R. Dice (1943) and other vertebrate zoologists such as W. F. Blair (1950), A. H. Miller (1951), and H. M. Smith (1949). Kendeigh (1961, 274) characterized biotic provinces as being “a continuous geographic area that possesses a fauna distinguishable, at the species and subspecies levels, from the fauna of adjacent areas, at least to a certain degree.” The application of a modified biotic province concept (e.g., Holman and Holman 2003) divides Michigan into very broad natural regions (see fig. 8). The Carolinian Biotic Province in the lower part of the Lower Peninsula is dominated by deciduous hardwood forests. The Canadian Biotic Province, which is located in the upper part of the Lower Peninsula and throughout the Upper Peninsula, is dominated by a mixture of deciduous hardwood and coniferous forest. In between the Carolinian and Canadian provinces lies a vegetational transition zone. This transition zone is much more vertically extensive in the western part of the Lower Peninsula than it is in the eastern part because of the warming effect of Lake Michigan and the direction of prevailing southwest winds.

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FIG. 8. The biotic provinces in Michigan and the transition zone between them. All of the Upper Peninsula (not shown) also lies in the Canadian Biotic Province. Illustration by the author, from Holman and Holman (2003), courtesy of the University of Michigan Press.

The Mason-Quimby Line The Mason-Quimby Line (often abbreviated MQ) reflects the early publications of two University of Michigan archaeologists, R. J. Mason (1958) and G. I. Quimby (1958, 1960), both of whom were interested in the hunting activities of the Paleo-Indians of the postglacial Pleistocene. Thus, the Mason-Quimby Line was originally drawn up to indicate the northernmost occurrences of Paleo-Indian fluted spear points and the mastodonts that were supposedly hunted by these people (see fig. 9). The Mason-Quimby Line today depicts the northernmost records of most (probably all) of Michigan’s Pleistocene vertebrates. The best explanation for this distribution is thought to relate to the position of the ice sheet in Michigan during its final retreat (Holman 2001a). About 14 ka BP the edge of the ice was about thirty-five miles south of the Mason-Quimby Line, but by 13 ka BP it had retreated to about seventy miles north of the line. A retreating ice sheet leaves a mass of essentially sterile gravel, sand, and mud in its wake that must be recolonized by plants for stable communities to develop. It would seem that it would take considerable time for such communities to develop in such sterile material,

1. Introduction: Michigan as a Herpetological Habitat

especially considering the cold climate that must have existed near the margin of the ice. Undisputed records of postglacial Pleistocene vertebrates in Michigan span a relatively short time of about 12.5 to 10 ka BP. Thus, it seems highly possible that during this interval, plant communities north of the Mason-Quimby Line were not stable enough to sustain the number of vertebrate species necessary to contribute significantly to the fossil record. This lack of stability in plant communities north of the MQ would certainly have affected the timing of postglacial reentry of Michigan amphibians and reptiles.

quarreled with that, and being a college teacher myself for many years, have put that idea to practice whenever possible. Thus, I am much happier with the Michigan Regional Landscape Ecosystems (MRLE) than with other attempts to categorize the “natural divisions” of the state and have no problem with the defined hierarchical subunits (see Barnes and Wagner 2004, 362–63, fig. 27a and b). Here, however, only the four major regions will be explained (see fig. 10).

Michigan Regional Landscape Ecosystems As a graduate student at the University of Florida in the 1950s, I was privileged to take courses in ecology with renowned biologist and conservationist Archie Carr, who told us that ecology was basically the study of how to describe simple concepts with fancy words. I have never

Fig. 10. The four Michigan Regional Landscape Ecosystems. Illustration by the author.

Fig. 9. The broken line depicts the Mason-Quimby Line. North of this line, there is no undisputed evidence of Pleistocene vertebrates and very little evidence of Paleo-Indian activity. The object to the left is a spear point of the type Paleo-Indians used to kill mastodonts, and the object directly below it is the top surface of a mastodont tooth. To the right are a mastodont and her baby. Illustration by the author.

The four major units are recognized on the basis of climate and physiographic features, which in turn are related to soil development and structure as well as the occurrence of plant and animal communities. Two regions—I and II—are recognized in the Lower Peninsula and another two—III and IV—in the Upper Peninsula. Region I is warmer throughout the entire year than the other three. Moreover, it has a plant growing season that is longer and less variable than the three regions to the north. Region I is characterized by widespread lake plains of sand and clay, ground moraines, and various end features left by the ice sheets. The ridges in Region I are lower than those in II, III, and IV, and range from about fifty to one hundred feet high. Loams and clays are the dominant soils, and sands are less common. Region I vegetation includes many southern plant species, resulting in plant communities that are more diverse than in the

9

The Amphibians and Reptiles of Michigan

northern three regions. Moreover, many animal species that occur in Region I are absent in II, III, and IV. Region II has a much different climate than that of Region I. Three factors are involved in this. Region II has a more northern latitude, it is surrounded on three sides by the Great Lakes, and the upland areas are more extensive and higher than in Region I. These high upland areas contribute to a cooler and more variable climate than in Region I, and there is a greater chance for frost during the plant growing season. Moreover, precipitation is not only affected by the more extensive upland areas but by the bordering lakes as well. Soils are more sandy in Region II than in I, and extensive, thick glacial deposits are widespread. Lowland swamps and bogs are more abundant and often more acidic than they are in I. The diversity of plant species is less because of the lack of southern species. Region III, which is roughly the eastern half of the Upper Peninsula (see fig. 10), is characterized by its lower elevation and comparatively young Paleozoic bedrock that consists of patches of Devonian strata north of the Straits of Mackinac and more extensive Silurian and Ordovician rocks farther north and west. The plant growing season of 120–40 days is similar to that in Region II. The three Great Lakes that surround Region III (Superior, Michigan, and Huron) tend to modify extremes in temperatures and to reduce the severity of thunderstorms. The soils in Region III are thin and composed mainly of poorly drained sand and clay, with a presence of bedrock near the surface in some areas. Northern coniferous trees occur in low, moist areas, and uplands are dominated by mixed hardwoodconiferous forest. Region IV comprises roughly the western portion of the UP. Here very ancient Precambrian and Cambrian bedrock occurs (see fig. 2), with the Precambrian rocks making up a particularly complex system. Relatively frequent outcrops of these rocks can be seen in the countryside. The region contains many uplands as well as low mountains. The climate in Region IV is the most continental of all four of the Michigan regions, being warm during the growing season and very cold in the winter. The Region IV climate is more extreme mainly because there is less lake moderation. Northern hardwood-coniferous forests are abundant, with white pine, red pine, and oak dominating upland communities.

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Modern Herpetological Habitats The previous discussion about the history and attributes of Michigan’s landforms and climate can help us understand the historical and present distribution and species diversity of Michigan’s amphibians and reptiles. Michigan’s modern herpetological habitats will be described under the general headings of (1) forests; (2) grasslands; (3) lakes and ponds; (4) marshes, swamps, bogs, and fens; (5) rivers and streams; and (6) urban habitats.

Forests Forests form the dominant natural cover type in the state of Michigan today and are the most definitive natural feature of the state. Dickmann and Leefers (2003) have provided definitions and descriptions for the major forest cover types in Michigan, and these are summarized in the following sections. Wet deciduous (elm-ash-cottonwood) forest cover type The wet deciduous forest cover type is principally composed of American and slippery elms, silver maple, black and red ashes, and cottonwood (typical species). Red maple, black willow, quaking aspen, sycamore, hackberry, pin oak, bur oak, and swamp white oaks are other principal taxa. This forest type is found in mesic (moist) to hydric (wet) situations in basic lacustrine (lake or pond) lowlands and in depressions or riparian (river

FIG. 11. A wet deciduous riparian habitat of the Coldwater River drainage system of Branch County, Michigan. Here I have observed American Bullfrogs, Northern Green Frogs, Blanding’s Turtles, Midland Painted Turtles, Eastern Milksnakes, Copper-bellied Watersnakes, Common Watersnakes, Eastern Gartersnakes, and Eastern Massasaugas. Photograph by the author.

1. Introduction: Michigan as a Herpetological Habitat

or stream bank) corridors mainly in Region I (see fig. 11). The ecological role of elms has been highly modified by Dutch elm disease. This forest type is estimated to occupy about 1,627,000 acres in the state. Oak (oak-hickory) Region I forest cover type The oak Region I forest cover type is composed of red, black, white, and northern pin oaks (typical species) and bitternut, pignut, and shagbark hickories, black walnut, white ash, basswood, bur and scarlet oaks, sassafras, bigtooth and quaking aspens, red maple, black cherry, and red cedar (other principal taxa) (see fig. 12).

Fig. 13. Northern oak–hickory assemblages can be found in the northern part of the Lower Peninsula. This woodland stand grows on a relatively high area atop the Port Huron Moraine near Lake City, Missaukee County, Michigan.Photograph by the author.

elms, bitternut hickory, and red maple (other principal taxa) (see fig. 14). This forest cover type is found in mesic to wet mesic situations in cool, fertile, mediumtextured upland soils. This type occurs only in Region I. Fig. 12. A southern oak–hickory assemblage near Warren Woods, Berrien County, Michigan. The shagbark hickory that dominates the foreground is a characteristic species. These dry forests in Michigan are home to such interesting species as Eastern Box Turtles and Central Ratsnakes. Photograph by the author.

Oak (oak-hickory) Region II forest cover type The oak species in the oak Region II forest cover type are mainly northern pin oak and white oaks (see fig. 13). Important associated species include red oak, aspen, red maple, and black cherry. This forest cover type grades into the pine type. Both the Region I and Region II oak types are found in dry mesic (somewhat moist) to xeric (dry) situations in glacial outwash, sandy lake plains, gravelly ridges, hills, and sand dunes. The total area occupied by these two oak forest cover types in Michigan is estimated to be only about 764,000 acres. Mesic deciduous (beech-maple) southern forest cover type The mesic deciduous southern forest cover type is composed principally of sugar maple (typical species) and black maple, beech, red and white oaks, tulip poplar, basswood, white ash, black cherry, American and slippery

Fig. 14. A depiction of a mature beech-maple assemblage in Baker Woodlot, a Michigan State University property located near the campus. This scene is from a diorama in the Michigan State University Museum. In the past, Blue-spotted Salamanders, Spotted Salamanders, Blanding’s Turtles, and Eastern Gartersnakes have been seen in such settings in the woodlot. Courtesy of the Michigan State University Museum.

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The Amphibians and Reptiles of Michigan

Mesic deciduous (northern hardwoods) northern forest cover type The mesic deciduous northern forest cover type is composed principally of sugar maple (typical species) and beech, yellow birch, red oak, basswood, red maple, hemlock, white pine, and white spruce (other principal taxa) (see fig. 15). This forest type also occurs in mesic to wet mesic situations in cool, fertile, medium-textured upland soils. It occurs in Regions II, III, and IV. Both mesic deciduous forest cover types together occupy about 7,161,000 acres in Michigan.

This forest cover type occurs in mesic to wet mesic cool, fertile, medium-textured upland soils, principally in Regions II and III. This type occupies about 3,213,000 acres in the state.

FIG. 17. A dense aspen forest stands behind the planted spruce next to a highway in Kalkaska County, Michigan. Photograph by the author.

FIG. 15. A mature northern mesic beech-maple forest stand in western Traverse City, Michigan. Photograph by the author.

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Aspen forest cover type The aspen forest cover type is composed of bigtooth and quaking aspen (typical species) and paper birch, red maple, balsam fir, and red and white pines (other principal taxa) (see fig. 17). This cover type occurs in dry to wet mesic highly disturbed soils of multiple origins in Regions II, III, and IV. It occupies about 3,157,000 acres in Michigan.

Pine forest cover type The pine forest cover type is composed mainly of jack, red, and white pines (typical species) and northern, pin, red, and white oaks, paper birch, bog tooth and quaking aspen, and red maples (other principal taxa) (see fig. 16).

Wet coniferous-boreal forest cover type (“cedar swamps”) The wet coniferous-boreal forest cover type is composed of black and white spruce, balsam fir, tamarack, and northern white cedar (typical species), and white and

FIG. 16. A forest of white pine, red pine, and paper birch at Harwick Pines, Crawford County, Michigan. I have found Northern Ring-necked Snakes at the edges of such forests in Roscommon and Crawford counties, Michigan. Photograph by the author.

FIG. 18. A wet coniferous-boreal forest (“cedar swamp”) near the Manistee River in Kalkaska County, Michigan. Photograph by the author.

1. Introduction: Michigan as a Herpetological Habitat

jack pine, red maple, black ash, balsam poplar, yellow birch, and speckled alder (other principal taxa) (see fig. 18). This forest cover type occurs in wet mesic to very wet, cold, mainly acid bogs, peaty lacustrine lowlands, wet depressions, shorelines, and riparian situations in Regions II, III, and IV. This type occupies about 2,673,000 acres in the state.

Grasslands A map of presettlement vegetation circa 1800 (Comer, Albert, and Austin 1998) shows that grasslands and savanna were a prominent feature in southern Michigan (Region I), much different from the situation today (see fig. 19). Now such features exist only as small relict patches. Dickmann and Leefers (2003) reported that about 730,000 acres of true prairie composed of grasses and forbs were scattered throughout much of Region I and also existed in relatively small patches in Regions II, III, and IV (besides fig. 19, see also Barnes and Wagner 2004, 380–81, fig. 31; Dickmann and Leefers 2003, 102–3, figs. 5.4 and 5.5, for more detailed maps).

Berrien, Clinton, Eaton, Ingham, Livingston, Shiawassee, Van Buren, and Wayne counties were also prairie (Kenoyer 1929, 1933). These prairies usually occurred in flat areas with well-drained soils high in organic content and derived from glacial outwash. Moreover, extensive wet prairies along the shores of Lake Erie and Saginaw Bay were located behind coastal dunes or marshes (Albert 1995). At present, the mesic tallgrass prairies have become rich farmlands, and most of the wet prairies have been drained to create farmland or enhance development projects. Two basic types of Michigan prairies are recognized. True prairies are treeless, although woody shrubs may occur there. Brush prairies, however, contain scrubby trees (primarily oaks) as well as grasses and forbs. Both true and brush prairies are thought to have been maintained to improve wildlife production and travel routes for native people (Curtis 1959). Mixed in with the Michigan prairies were so-called oak savannas that consisted of open grasslands containing scattered areas of trees. These were communities that were transitional between the treeless prairies and the closed forest in Region I. These parklike features occupied about 1,800,000 acres, with the defining features being the presence of scattered, gnarled trees, mainly bur oak, white oak, and black oak with some hickory, black cherry, aspen, and cottonwood. These trees existed as individuals or in open groves. The presence of prairies and oak savannas in the near past and the recent elimination of such habitats are important considerations in the present distribution of amphibians and reptiles in the state.

Lakes and Ponds

Fig. 19. The location of a mixed grassland and oak savanna trackway across southern Michigan in about 1980 (stippled area). The open circles indicate the cities of (1) Kalamazoo, (2) Lansing, and (3) Ann Arbor. Illustration by the author.

Dickmann and Leefers (2003) report that (circa 1800) 4 percent of the area of Cass County, 6 percent of Calhoun County, 8 percent of Kalamazoo County, and 11.5 percent of St. Joseph County consisted of mesic tallgrass prairie. Moreover, significant parts of

Michigan has more than thirty-five thousand officially mapped lakes and ponds. Other than the fact that lakes are larger than ponds, defining the difference between the two is ambiguous. People have tried various ways, but I find the best distinction is that anybody running a motorboat on a pond usually looks silly. Most of Michigan’s natural lakes and ponds are glacially derived, one way or another. Moreover, those that are not “managed” are undergoing the natural process of succession (filling in), which is one more problem future generations will face.

13

The Amphibians and Reptiles of Michigan

Large inland lakes in Michigan are plentiful, and at least twenty of them are of significant size (see Sommers 1977). The five largest are in Region II and are, in order of size, Houghton in Roscommon County, Torch in Antrim County, Charlevoix in Charlevoix County, and Burt and Mullet in Cheboygan County. From east to west, Mullet, Burt, and Crooked Lakes and their connecting rivers form an inland waterway connecting Lake Huron to Lake Michigan. Several thousand years ago, when the lake levels were higher, this inland waterway cut off the upper tip of the Lower Peninsula from the mainland. Michigan lakes can be divided into three major categories. Oligotrophic lakes produce a relatively small number of organisms (living things). They are mainly deep, clear lakes that have an abundant supply of oxygen and a cold, oxygenated bottom layer all year long. In Michigan, large oligotrophic lakes were produced by wide, deep glacial gouging. The classic example is Higgins Lake (see fig. 20) in northwest Roscommon County (Region II). Oligotrophic lakes generally have a low diversity of associated amphibians and reptiles (“associated” meaning those living in or near the lake), especially the fully aquatic herp species, in part because their waters are generally cooler and lack high populations of food organisms as well as the aquatic vegetation used as cover or food by these animals.

FIG. 20. Higgins Lake—a large, deep, clear oligotrophic lake—is located mainly in Roscommon County, Michigan, but extends into Crawford County. Photograph by the author.

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Eutrophic lakes (figs. 21 and 22) are rich in plant and animal life. They are relatively shallow lakes that are usually not particularly clear because they contain abundant organic material throughout the water column. Eutrophic lakes are the most abundant type of inland lake in Michigan. The largest in the state is Houghton Lake, just south of Higgins Lake in Roscommon County. Of the three classes of Michigan lakes, eutrophic lakes have the largest number of associated amphibians and reptiles.

FIG. 21. This natural eutrophic lake in southeastern Grand Traverse County, Michigan, maintained a thriving Common Mudpuppy colony as recently as the early 1980s, but these salamanders are now extinct at this location. Today, small populations of Northern Green Frogs, Eastern Snapping Turtles, and Northern Map Turtles as well as a moderate number of Midland Painted Turtles occur here. Photograph by the author.

FIG. 22. Lake Ovid in Clinton County, Michigan, a eutrophic lake created by the damming of the Little Maple River, has a good population of American Bull Frogs and Northern Green Frogs along with a meager population of Northern Leopard Frogs. Eastern Snapping Turtles, Midland Painted Turtles, and Blanding’s Turtles appear to be doing well in the habitats provided by this artificial lake, as are Common Watersnakes. Photograph by the author.

1. Introduction: Michigan as a Herpetological Habitat

Fig. 23. This temporary woodland pond near Lansing, Michigan, has provided a good breeding site in the early spring for Wood Frogs. Photograph by James H. Harding.

Dystrophic lakes (and ponds) are relatively abundant in Michigan. These lakes support rather specialized animals and plants. Because dystrophic lakes lack calcium, they are acidic, and decomposition of organic matter occurs slowly. Thus the water is often tea colored, and undecayed organic matter accumulates on the bottom as peat. These lakes eventually develop into peat bogs as they fill in. Dystrophic lakes have more associated amphibian and reptile species than oligotrophic lakes but fewer than eutrophic lakes. Two specialized types of ponds need special mention. Temporary woodland ponds, or vernal ponds (see fig. 23), are so shallow they normally dry up during the summer months and are unsuitable for occupation by permanently aquatic animals such as fish. These ponds are absolutely essential structures for many species of salamanders and frogs in Michigan. Amphibians breed and lay their eggs in these places where both the eggs and larvae are free from predation by fishes. Beaver ponds are created by the activities of beavers, which dam up small streams to create shallow, sometimes quite extensive bodies of water (see fig. 24). Amphibians and some reptiles frequent beaver ponds, and turtles may be found sunning on fallen dead trees killed by pond flooding or on the beaver lodges themselves.

Marshes, Swamps, Bogs, and Fens Marshes, swamps, bogs, and fens can all be considered “wetlands” because they are all natural areas of low-lying

land that are either submerged or periodically inundated by water. Wetlands are among the most interesting and fragile habitats in Michigan. Wetlands undergo continual change because of the natural process of ecological succession. They are also degraded or destroyed by humans’ drainage projects and consequent development. A marsh may be defined as an area of more or less continuously waterlogged soil that is dominated by emergent plants (fig. 25). A swamp is similar to a marsh except that trees form a part of its structure (see fig. 11). Bogs, on the other hand, may be defined as areas with a peaty substrate, rich in organic debris but low in mineral

Fig. 24. This beaver pond in southern Kalkaska County, Michigan, maintains Eastern Newts, Northern Green Frogs, Midland Painted Turtles, Blanding’s Turtles, and Common Watersnakes. Photograph by the author (in part).

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The Amphibians and Reptiles of Michigan

and reptiles in Michigan, whereas bogs and fens have fewer herpetological associates, although those that do occur may be specialized for these habitats.

Rivers and Streams

FIG. 25. A marsh surrounded by coniferous forest in Roscommon County, Michigan. Photograph by the author (in part).

nutrients. The vegetation in bogs is composed of shrubs, sedges, and mosses such as sphagnum. Bogs are much more acidic than marshes, primarily because of the presence of sphagnum moss. A grassy bog with scattered, stunted conifers is called a muskeg (fig. 26). A bog-like wetland that is composed of mineral-rich soil, usually dominated by grasses and sedges, and that has a winter water table at or above ground level is a fen. Because of the absence of sphagnum moss and the higher pH, fens are often referred to as “alkaline bogs.” Marshes and swamps are both excellent habitats for both amphibians

Michigan is laced with a network of rivers and their tributaries, which mainly drain into the Great Lakes. The two largest river systems in the Lower Peninsula are the Saginaw in the eastern part of Region I and the south-central part of Region II, and the Grand in the central and western part of Region I. These two systems flow over areas of relatively low elevation. The Grand River system drains into Lake Michigan at Grand Haven in Region I, and the Saginaw River drains into Lake Huron’s Saginaw Bay near Essexville in the northern part of Region I.

FIG. 27. A section of the Manistee River in Kalkaska County, Michigan, that can be characterized as a swift stream. Photograph by the author (in part).

FIG. 26. A leatherleaf bog in southeastern Grand Traverse County, Michigan, is typified by the small white pines in various stages of growth emerging from the mass of leatherleaf plants. Northern Spring Peepers, Western Chorus Frogs, and Wood Frogs are the most common breeding frogs in this particular bog. Photograph by the author (in part).

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The two largest river systems in the Upper Peninsula are the Manistique in the western part of Region III and the Menominee in the south-central part of Region IV. The Manistique River drains into Lake Michigan at Manistique, and the Menominee River drains into Lake Michigan’s Green Bay at Menominee. The rivers and streams in Regions III and IV can be rather swift because of the relatively high elevations in the areas, and although the water flows through sandy soil, it is usually weakly tea-colored because it travels through mixed coniferous/ deciduous forests (fig. 27). Rivers and streams in Regions I and II have lazy sections because of the lower elevations and flatter topography that they flow through; here the water is usually much darker than weak tea because of the soil types and agricultural runoff (see fig. 28).

1. Introduction: Michigan as a Herpetological Habitat

Fig. 28. A slow stream that forms the outlet of a medium-sized eutrophic lake in Grand Traverse County, Michigan. Rocks piled up here to maintain the bank form a shelter for Northern Ribbonsnakes and Eastern Gartersnakes. Northern Green Frogs and juvenile Eastern Snapping Turtles characteristically hide in the silted-in edges of this stream. Photograph by the author (in part).

All the different types of rivers and streams—even the highly polluted ones—may have characteristic herpetological associates.

Urban Habitats Although intensively developed urban areas are unwelcoming places for reptiles and amphibians, urban and suburban regions usually include parklands and undeveloped or abandoned properties that may offer “islands” of useable habitat that can harbor herp populations. Species that can survive under these often challenging conditions are typically those that have rather generalized ecological and food tolerances, such as Eastern Gartersnakes, Green Frogs, American Toads, Painted Turtles, and Common Snapping Turtles. Some rare species, including the Eastern Foxsnake and Blanding’s Turtle, and environmentally sensitive species, such as the Northern Leopard Frog, Eastern Spiny Softshell, and Common Mudpuppy, can do well in urban landscapes provided their basic natural history needs are met. (See Mitchell et al. 2008 for an extensive review of various aspects of urban herpetology.) I moved to East Lansing in 1967 to a house very near Michigan State University, and I have dwelled there ever since. The moderate-sized backyard has a low area that temporarily holds standing water when the snow melts. For about ten years after moving to this location, I frequently saw amphibians and a reptile species in the

spring and summer. American Toads and Gray Treefrogs were the most common amphibians that appeared. Occasionally I would see an Eastern Red-backed Salamander in a wooded area of the yard under some flat rocks. Eastern Gartersnakes were common enough that I had to be alert for them when mowing the grass. Since 1977, though, I have not seen a herp in the yard. This is perhaps in part because of increased traffic and area development, but perhaps also because the yard is lower than surrounding yards, and chemicals used to promote lawn development elsewhere may accumulate there. I deeply fear that in at least the eastern third of the United States, we are rapidly heading toward a situation in which the diversity of flora and fauna will be much reduced, similar to what started in England long ago. That small country came under cultivation many hundreds of years ago and then experienced massive population growth and urbanization during the Industrial Revolution. The result is that no definitive stands of native forests exist in England; these were largely replaced by exotic species that could adapt themselves to poor soils, artificial woodlands, parklands, and urban situations. Many of these situations are attractive and even beautiful, but they are not natural. Patterns of glaciation and the isolation of land masses in the British Isles during the Pleistocene resulted in only six species of amphibians and six species of reptiles presently being native to Britain (see Holman 1998). Even with the massive human modification of the environment, the twelve native species in Britain were, at one time, all considered plentiful (Frazer 1983). But by 1930, the Natterjack Toad (Bufo calamita), a species common on the European continent but with a scattered, spotty distribution in Britain, had vanished from some localities and is presently seriously endangered. Shortly after, the Smooth Snake (Coronella austriaca), confined to southernmost England, and the Sand Lizard (Lacerta agilis), located in just southernmost England and an area near the Irish Sea, were determined to be gravely endangered. The last time I spoke in person to British herpetologists was in 2001, and they lamented that natural populations of all twelve native species were depleted and that most amphibians were now living in very small constructed ponds in urban or semiurban areas. These ponds average about twelve feet across and

17

The Amphibians and Reptiles of Michigan

are well tended. The species that seems to fare the best in them is the small Common Newt (Triturus vulgaris). How much more satisfying it would be to find them in natural woodland ponds. With the decline of many formerly common amphibian and reptile species in Michigan over the last few decades, perhaps urban Michiganians should be encouraged to build backyard ponds for “pocket” habitats to benefit herps and other wildlife.

History and Status of Michigan Herpetology The history of Michigan herpetology is strongly associated with institutions of higher learning, including academic departments, biological research stations and wildlife preserves, extension services, and professional academic societies. Other contributing institutions include the Michigan Department of Natural Resources (MDNR) and the Detroit Zoological Park.

Institutions of Higher Learning and Their Satellites Largely because of a sympathetic group of administrators, the University of Michigan became the leading force in the development of herpetological research in the state. Much of the following section on the development of such studies at the University of Michigan is based on material available online from the Division of Herpetology in the Museum of Zoology. Michigan became the twenty-sixth state in the Union on January 26, 1837, and the formal history of herpetology as a science in the state essentially began on June 21, 1837, when the Michigan State Legislature authorized funds for a “Cabinet of Natural History” at the University of Michigan. One of the earliest specimens to reside in the University of Michigan facility was an American Toad (Bufo americanus) from southeastern Michigan, donated by Professor Abram Sager in 1837. By 1863, 212 specimens of amphibians and 336 reptiles were in the “cabinet” (Winchel 1864). Many of these animals were collected by Lt. William P. Trowbridge while on duty along the Pacific Coast between 1853 and 1856. Other particularly significant early herpetological collections donated to the University of Michigan were made by Professor Joseph Beal-Steere and came from South American and Asian localities

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during his trip around the world (1870–75) and from other expeditions later on (1879–88). Unfortunately, few specimens from the Trowbridge and Beal-Steere collections are available today. In 1881 the Cabinet of Natural History was renamed the Museum of Natural History of the University of Michigan (Ruthven 1910). In 1913 the Board of Regents of the university renamed it the Museum of Zoology and appointed Alexander G. Ruthven as its director; by 1917 a Division of Amphibians and Reptiles was officially recognized. Ruthven labored to secure funds for the present museum’s building, which opened in 1928. He then became the president of the university, yet he did not give up his curatorship until 1936. This may have been the first (and only?) time a herpetologist has been president of a major university. Ruthven was one of the outstanding herpetologists of his time, and he published about 160 professional papers. His (and his coauthors’) Herpetology of Michigan (1912 and 1928) was a pioneering model for state herpetological monographs, and his format is still used today. His classic “Variations and Genetic Relationships of the Garter-Snakes,” published in 1908, is still a model for the study of geographic variation in a reptile species. Turning to other early Michigan herpetologists, William H. Smith in 1876 was awarded one of the first two doctoral degrees to be given by the University of Michigan. His broadly focused thesis was titled “The Zoology of the Anoura and Caecilia,” a work that he quickly revised and published as a monograph (W. H. Smith 1877). Other noteworthy Michigan herpetologists were Crystal Thompson and Helen T. Gaige, who were both coauthors of the two Herpetology of Michigan editions with Ruthven. Thompson also published several herpetological papers in the Michigan Academy of Science, one with Gaige. Gaige was given a curatoral title in 1919, a position she occupied until her retirement in 1945. Norman Hartweg was curator in the Division of Herpetology of the Museum of Zoology at the University of Michigan from 1934 to 1964, Charles F. Walker from 1947 to 1975; and Donald W. Tinkle from 1965 until his untimely death in 1980. Arnold G. Kluge was a division curator from 1967 to 2003, and Ronald A. Nussbaum arrived in 1983 and remains a curator at

1. Introduction: Michigan as a Herpetological Habitat

this writing. Other University of Michigan faculty members who were not curators in the Division of Herpetology but were all outstanding herpetologists are Reeve M. Bailey, Frank N. Blanchard, William R. Dawson, Carl Gans, Howard K. Gloyd, Nelson G. Hairston, George W. Nace, Laurence C. Stuart, and Frederick H. Test. During the last few years of its development, the Division of Reptiles and Amphibians has grown to house about 400,000 specimens. Since Ruthven’s time, more than fifty PhD students have earned their degrees under the direction of division curators. Many faculty members and curators as well as graduate students from the University of Michigan have contributed to Michigan herpetological studies in one way or another. The division’s website provides holdings and locality data for Michigan’s amphibians and reptiles, maintained by collections manager Greg Schneider. The Michigan State University Museum was founded in 1857 by President Joseph R. Williams, who called for the establishment of cabinets of natural science specimens at the Michigan Agricultural College. This became the Michigan Agricultural College Museum, which changed its name in 1925 to the Michigan State College Museum, in 1955 to The Museum, Michigan State University, and finally in 1982 to the Michigan State University Museum. A Division of Cold-Blooded Vertebrates was created in 1955 by director Dr. Rollin H. Baker, who established the MSU Museum in its present form. This division was curated by Dr. Michael Ovchynnyk, an ichthyologist, who managed a collection of fishes, amphibians, and reptiles. Dr. Ovchynnyk died in 1971, when I was curator of vertebrate paleontology at the museum, and I was given the opportunity to curate the fishes, amphibians, and reptiles as well as the vertebrate paleontological material. Dr. Marvin M. Hensley joined the Department of Zoology at Michigan State in 1957 and was closely associated with the Michigan State Museum until his retirement in 1987. Hensley was active in herpetological research and teaching at Michigan State and supervised, among other students, the doctoral studies of J. Whitfield Gibbons, Dean Premo, and William Wakasey, all respected biologists. Hensley donated his large herpetological collection to the MSU Museum before his retirement and bequeathed money for the maintenance of MSU natural history collections before his death in 2000.

Today the unit that manages the natural history component of the Michigan State University Museum is designated the Division of Natural Science and includes the collection of fishes, amphibians, reptiles, birds, mammals, and vertebrate fossils. Michael Gottfried, a paleoichthyologist, is presently responsible for the preserved fishes, amphibians, and reptiles. At present the MSU Museum has about 18,600 amphibian and reptile specimens, mainly representing Michigan and Mexico. The Michigan specimens were collected mostly by M. M. Hensley and his students, J. H. Harding, and me. James H. Harding is currently an MSU Museum staff member in the Division of Education. Harding is a well-known herpetologist who has been for several years chairperson of the Technical Advisory Committee on Amphibians and Reptiles, which advises the MDNR on herpetological issues. Harding has published Amphibians and Reptiles of the Great Lakes Region (1997) with the University of Michigan Press, and together we coauthored three popular field guides published by Michigan State University: Michigan Turtles and Lizards (1997), Michigan Frogs, Toads, and Salamanders (1992), and Michigan Snakes (2006). Biological stations and preserves administered by Michigan universities have also been important in the history of Michigan herpetology. The University of Michigan Biological Station at Douglas Lake, near Pellston in Cheboygan County—endearingly known to many as the “Bug Station”—opened in 1909 and continues to be one of the most highly regarded biological stations in North America. The station has an active teaching agenda, and field-oriented courses are taught by up to twenty visiting professors each summer. Research is paramount there, and the number of scientific papers published based on research conducted at the station is prodigious. My parents took me by the Bug Station when I was fourteen, a year after World War II had ended and we had gasoline again. I was thrilled to see students in a lab handling and identifying living Midland Painted Turtles, Northern Ribbonsnakes, and Eastern Gartersnakes. This event set me on the road to becoming a professional herpetologist. I am pretty sure the teacher of the lab must have been Dr. Frederick H. Test, a herpetologist on the faculty of the University of Michigan who added many herpetological specimens to

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The Amphibians and Reptiles of Michigan

the research collections at the station. A couple of years earlier, Charles W. Creaser had published “The Amphibians and Reptiles of the University of Michigan Biological Station Area in Northern Michigan” (1944). The W. K. Kellogg Biological Station (KBS) of Michigan State University is equally well known, both statewide and nationally. Located on the eastern shore of Gull Lake, which traverses the boundary of Barry and Kalamazoo counties, KBS is unique because it is the only large experimental ecological facility in the northern oak-hickory forest region. This station has an exceptional physical plant that supports both education and research, an excellent onsite professorial staff, and a networked computer facility managed by full-time professionals. An undergraduate course in herpetology has been taught intermittently at KBS by such notable herpetologists as J. Whitfield Gibbons and James H. Harding. The Central Michigan University Biological Station, located on Beaver Island in northern Lake Michigan off the coast of Emmet County, has been the site of numerous herpetological research studies. Beaver Island has seven inland lakes as well as three satellite islands nearby. Nine undergraduate and three graduate summer courses are presently offered there by professors from Central Michigan University as well as visiting faculty. Fields of study at the station include biology, botany, zoology, ecology, ethology, meteorology, and astronomy. From 1969 to date, forty-one papers have been published that grew out of research conducted at the CMU station. Dr. James C. Gillingham, a behavioral and ecological herpetologist, was the director of the station from 1985 through 2009 and has been a major force in herpetological field research in Michigan. Significant research has involved Green Frogs, Painted Turtles, Eastern Gartersnakes, Northern Ribbonsnakes, Northern Watersnakes, and many other amphibians and reptiles. The E. S. George Reserve, administered by the University of Michigan and the University of Michigan Museum of Zoology, is a world-class research area in southeastern Michigan’s Livingston County. There, woodlands, fields, lakes, ponds, swamps, marshes, and bogs are available for long-term studies of amphibians and reptiles. The reserve may be best known for an important long-term study of the Blanding’s Turtle (Emydoidea blandingii), started by Owen J. Sexton (1953–

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55) and continued intermittently by Henry M. Wilbur (1968–73), Donald W. Tinkle and Justin D. Congdon (1975–79), and Justin Congdon and associates (1980– 2007) (see Congdon et al. 1993). Many other herpetological studies have been conducted at the George Reserve as well. The Michigan State University Cooperative Extension Service has been an important unit with regard to the herpetology of Michigan. MSU Extension hosts a program called the Michigan Natural Features Inventory (MNFI), whose mission is to identify, evaluate, and monitor Michigan’s rarest species and exceptional examples of natural communities and to provide that information to both the public and private sectors for decision making that will affect Michigan’s biological diversity. The MNFI was established in 1980 and maintains an important and continually updated database on the state’s rare or unique natural features. MSU Cooperative Extension Service county agents have long been available for questions about all kinds of animals that people find, see, or think they have seen, including amphibians and reptiles. These agents are steadfast and dedicated in their efforts; if they cannot identify something, they keep at it until they find an expert who can. The Cooperative Extension Service published the previously noted series of field guides to Michigan amphibians and reptiles, dealing with turtles and lizards (Harding and Holman 1997); frogs, toads, and salamanders (Harding and Holman 1992); and snakes (Holman et al. 2006). These books, written to be understandable to the general public, including children, have been popular with the nonscientific and conservation community alike. Along with the large state universities, the smaller universities and private colleges of Michigan have contributed much to the herpetological knowledge of Michigan. Herpetologists who are now or have been recently on the faculty of some of the smaller institutions include Richard Bowker and John Rowe of Alma College, Ronald Gratz of Michigan Technological University, Brent Graves of Northern Michigan University, James Gillingham of Central Michigan University, and Craig Weatherby of Adrian College. All of these individuals have contributed to Michigan herpetology and together have supervised many student

1. Introduction: Michigan as a Herpetological Habitat

research projects on amphibians and reptiles. Many nonaffiliated individuals, who approach herpetology as an avocation, have also made significant contributions to herpetological knowledge in Michigan. The Michigan Academy of Science, Arts, and Letters (MASAL), with its headquarters now at Alma College in Alma, Michigan, was founded as the Michigan Academy of Science in 1894. In 1922 it expanded its academic coverage and changed its name to the present title. The twenty-four-member academic institutions of MASAL provide a substantial part of its infrastructure and financial support. The Michigan Academy facilitates scholarly exchange by way of its annual meeting, where scholarly papers are presented. A quarterly journal features peer-reviewed papers and news about research at Michigan colleges and universities. Over the years, MASAL has provided a fine forum for the exchange of ideas about Michigan’s natural history. Moreover, for the past two or three decades, numerous papers on amphibians and reptiles have been presented at annual meetings. MASAL’s journal was titled Reports of the Michigan Academy from 1900 to 1921, Papers of the Michigan Academy of Science, Arts, and Letters from 1922 to 1968, and the Michigan Academician from 1969 to the present. Well-known herpetologists who contributed articles to the journal, especially in the early years (through the 1940s), include Frank Blanchard, Charles Carpenter, Charles Creaser, Helen T. Gaige, Howard Gloyd, Graham Netting, Paul Risley, Alexander Ruthven, Frederick Test, Crystal Thompson, and Ranier Zangerl.

Other Important Herpetological Resources The Michigan Department of Natural Resources (MDNR) is a valuable source of information for anyone interested in Michigan amphibians and reptiles. The MDNR had its beginnings in the early 1800s at a time when many Michigan citizens were particularly concerned about exploitation of the state’s natural resources. In 1921 the State Legislature combined several units into one called the Michigan Department of Conservation (MDC). Also in that year, the governor appointed a citizen group called the Conservation Commission to provide direction for the MDC. Today that group is called the Natural

Resources Commission, and it still reports to the governor. In 1968 the MDC was renamed the Michigan Department of Natural Resources, and it has become an agency with a large number of field and administrative units. At present, the Endangered and Nongame Unit of the Wildlife Division and the ancillary MNFI programs have been giving the amphibians and reptiles of the state an increasing amount of attention. Presently the MNFI monitors the distribution and health of the state’s listed herpetological species. The MDNR website contains valuable information about herps that can be found through the search feature. Among other valuable herpetological material, illustrated, detailed pages on each Michigan threatened or endangered species are available as well as pages for each species currently recognized in the state. One of the outstanding herpetological programs of the MDNR is the Michigan Frog and Toad Survey (MFTS), which was initiated in 1988 to increase knowledge about the abundance and distribution of these amphibians. This inventory is an annual volunteerbased census of calling frogs and toads taken during the breeding season. It has been demonstrated that volunteers are capable of recognizing the calls of individual species but are not always able to estimate abundance as accurately as was hoped. But an evaluation of methods and data quality of this call survey in 2001 is being used to improve data collection methods and to better analyze and interpret data previously collected (Genet and Sargent 2003). In addition, in the early part of the twenty-first century, an ambitious effort was initiated in Michigan to catalog all amphibians and reptiles statewide. The Michigan Herp Atlas Project is an important tool in assessing the current status and distribution of amphibians and reptiles in Michigan. The Herp Atlas was coordinated by Lori Sargent of the MDNR and administered by the Kalamazoo Nature Center. In 2010, Herpetological Resource and Management, LLC (HRM) became the Herp Atlas program administrator. The Detroit Zoological Park, open year round in Royal Oak, Michigan, is a place to see living reptiles and amphibians, not only exotic species from around the world but Michigan natives as well. The Zoological Park

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The Amphibians and Reptiles of Michigan

was founded in 1928 and is committed to “celebrating and saving wildlife.” Its 125 acres contain exhibits constructed to be as natural as possible. The Holden Museum of Living Reptiles houses animals under conditions that often allow them to exhibit “natural” behavior. The National Amphibian Conservation Center (“Amphibiville”) at the Detroit Zoological Park is a world-class display of living salamanders, frogs, and toads. Species considered threatened or endangered have been successfully bred at both of these facilities. Efforts at the local level have also been important for Michigan’s herpetofauna. In 1995 the City of Ann Arbor, under the leadership of David Borneman, started Michigan’s first frog and toad program. Since 2000 it has been coordinated and managed by David A. Mifsud. In 2004 Mifsud began Michigan’s first salamander monitoring program for the City of Ann Arbor with great success. This program has lead to the confirmation and discovery of species in city parks and has been an effective tool for management of natural areas in the city.

Procedures for the Collection and Identification of Michigan Amphibians and Reptiles The legal and ethical ramifications of the study and collection of Michigan amphibians and reptiles as well as procedures for the identification of both modern and fossil herpetological species are important considerations for the herpetologist. Identification and classification are different activities. Classification is essentially the act of arranging animals and plants that have already been identified into a hierarchical series of related groups. Until about the early 1960s, unrestricted collecting of amphibians and reptiles was the norm in the United States. Legal restrictions were not in place in most states, and if they were, they were not taken seriously by either the collectors or enforcement officers. In the first half of the twentieth century, certain frog species were collected by the millions for dissection in biology labs, to be used as fish bait, or for food in the form of fried frog legs (Harding and Holman 1992). Moreover, all of the other amphibians and reptiles were exploited by fishermen, the pet trade, private collectors, and even a few university museums that decimated local populations from time to time. Today, laws regulating the collection of amphibians and reptiles are on the books in all fifty states and may

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be strictly enforced. Also, ethical standards for the humane treatment of amphibians and reptiles relative to their capture, transportation, housing, and experimental use have been published by the major herpetological organizations. The Fisheries Division of the MDNR has authority for promulgating and enforcing the rules regarding the take and possession of Michigan amphibians and reptiles. These rules are presented in detail in the section “Amphibians and Reptiles” in the annually published MDNR Michigan Fishing Guide. This booklet is free and available anywhere Michigan fishing licenses are sold. The regulations are also available through the MDNR website. The MDNR Wildlife Division oversees regulations and enforcement regarding those amphibian and reptile species officially listed as threatened or endangered in Michigan. Michigan amphibian and reptile species listed as “Threatened” or “Endangered,” and those considered to be of “Special Concern,” are fully protected from capture or possession, except under special scientific collection permits issued by the MDNR. Even the species not so listed receive some protection in the form of daily and general possession limits and closed seasons, and a Michigan sport fishing license is required to collect and possess unlisted species. The best guideline for anyone who wishes to collect or do research on amphibians and reptiles in Michigan is to know the current rules and to apply to the Fisheries Division of the MDNR in Lansing for a scientific collector’s permit, as necessary. To identify native Michigan amphibians and reptiles in the field or in hand using this book, follow these steps: 1. Look at the pictures until you find the species that most closely matches your specimen. 2. Check the identifying characters of the species in the book. 3. Check the range maps to see whether the species has previously been found in the area where you are. (If this is not the case, you have probably made the wrong identification.) If you think you are seeing an amphibian or reptile species that has never been found in Michigan or that occurs well outside of its mapped range, contact a Michigan herpetologist or MDNR biologist to confirm your identification.

1. Introduction: Michigan as a Herpetological Habitat

Most amphibian and reptile remains from Pleistocene, Holocene, or archaeological sites in Michigan occur as individual bones, bone fragments, or turtle shell parts. The identification of these bones to the species level is a tedious process, and in general, the more fragmentary the bone, the more difficult this will be. Scientists who identify vertebrate bones from “natural” Pleistocene or Holocene deposits call themselves vertebrate paleontologists; those who identify animal remains from archaeological sites call themselves zooarchaeologists. Essentially the same methods are used by both of these groups in the identification of their material. Trying to correctly identify fragmentary amphibian and reptile bones that occur in vertebrate paleontological or zooarchaeological sites only by looking at published photographs is difficult, although some people try. The preferred method is to compare the unearthed bones and fragments with a collection of cleaned and disarticulated modern amphibian and reptile skeletons. Such collections are usually found only in museums connected with larger colleges or universities. Acquiring the amphibian and reptile specimens to do this requires state and/or federally issued permits, and in many states, even dead specimens peeled off a roadway may need such documentation. Moreover, a series of each species is preferable so individual variation may be studied. For instance, a foramen (hole) in the lower jawbone of two or three American Bullfrogs may seem to indicate that this is a distinguishing character for the species. But an examination of the lower jaws of ten American Bullfrogs is likely to show that three or four of them lack this foramen entirely. Making good, disarticulated amphibian and reptile skeletons is at best a complex and dismal task. Researchers and museum preparators making skeletal specimens usually find that the best way to make lasting skeletons is by the maceration process. This involves putting the individual parts of the animal in a sealed jar of water to allow bacterial activity to break down the non-bony parts. After a few weeks in a warm place, the resulting rather odiferous material is poured through a tea strainer or sieve and the bones are collected and dried. Setting up a bone-producing unit in a museum or university department requires a combination of commitment and diplomacy by the would-be skeleton

maker and the tolerance of such activity by associates. The actual act of the identification of unearthed Pleistocene, Holocene, or archaeological site amphibian and reptile bones, simply put, involves going through the comparative skeletal collection until a good match between the modern and unearthed bone is found. Checking through a series of individual skeletons of that species to see whether individual variation negates the preliminary identification follows. When working on the identification of bones and bony fragments of amphibians and reptiles, scientists have found that certain elements are much more diagnostic than others. For instance, a frog femur may be difficult to identify, even to the family level, whereas the ilium may be more easily identified to the species level (see fig. 29). As a general rule, bones with an important role in the life of the animal, such as the ilium—which is intimately associated with frog locomotion (swimming or jumping for many “true frogs,” hopping or running for most toads, burrowing for spadefoot toads, or climbing for treefrogs)—are useful elements in the identification of fossils. Such bones usually (but not always) have a more complicated structure than other bones in the skeleton.

Fig. 29. Upper: A generalized frog skeleton in dorsal view with the major bones labeled. Lower: The right ilium of an American Bullfrog in lateral view. Illustration by the author and Jane Kaminski.

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The Amphibians and Reptiles of Michigan

Individual vertebrae are the elements that are most often used to identify salamander fossils (see fig. 30). One reason is that salamander vertebrae are among the most numerous and most solidly built bones in the salamander skeleton and thus are the elements most likely to fossilize. Another reason is that salamander vertebrae in several families are elaborated for aquatic locomotion or a combination of both terrestrial and aquatic locomotion, as occurs in the newts. Salamander humeri and mandibles (see fig. 31) also have been used with success in the identification of fossils of this group. Most vertebrae are not very useful in the identification of frogs and toads to the specific level except for the atlas that joins the head to the body and the sacral vertebra that joins the hip girdle to the body (see fig. 32).

FIG. 31. (A) Right humerus of a salamandrid salamander showing different views of the same bone as it is rotated. (B) Left mandible (“jaw bone”) of a salamandrid salamander, showing the medial view (top) and lateral view (bottom). Illustration by the author.

single shell bone element for identifying a turtle species is the nuchal bone (see fig. 33, A), while the second best bone element for turtles is the entoplastron (fig. 33, B). Sometimes entire turtle shells are found in Michigan archaeological sites. Lizard bones are identified mainly on the basis of jaw elements with teeth attached (see fig. 34). As far as I am aware, no lizard bones have been unearthed in Michigan. Snakes, on the other hand, which have been unearthed in Michigan, have been identified based on individual vertebrae. This is not surprising, as snakes have from about 125 to more than 400 vertebrae in their vertebral column (Holman 2000), and at least the centra of these vertebrae are very solidly built and likely to fossilize (see fig. 35). As a functional unit, the snake vertebral column is more complex and efficient than that of any other legless

FIG. 30. Left: A generalized salamander skeleton in dorsal view (from Cope 1889). Notice the long vertebral column compared to that of the frog in figure 29. Upper right: The middle trunk vertebra in dorsal view of a salamander of the Blue-spotted Salamander complex. Lower right: The same vertebra in ventral view. Illustration by (in part) Rosemarie Attilio.

Individual shell bones or fragments of turtle shell bones are the most common reptile fossils found in Pleistocene, Holocene, and archaeological sites, not only in Michigan, but all over the United States. The best

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FIG. 32. (A) Ranid frog atlas and (B) sacral vertebra, both in dorsal view. Illustration by the author.

1. Introduction: Michigan as a Herpetological Habitat

Fig. 34. Left dentary of a fossil skink lizard in (A) medial view and (B) lateral view. Illustration by Jane Kaminski.

Fig. 33. (A) Bones and (B) epidermal scutes of an emydid turtle shell. Bones: NUC, nuchal; N, neural; C, cervical; S, suprapygal; EPI, epiplastron; ENT, entoplastron; HYO, hyoplastron; HYPO, hypoplastron; and XIPHI, xiphiplastron. Scutes: V, vertebral; PL, pleural; AX, axial; ING, inguinal; G, glular; HU, humeral; PEC, pectoral; AB, abdominal; FEM, femoral; AN, anal. Illustration by James H. Harding, from Holman and Harding (1977), courtesy of the Michigan State University Museum.

vertebrate animal. Having lost the appendicular muscles along with the appendages themselves, snakes depend on a complex system of axial muscles to move the body (see Cundall 1987). The muscles attach to the many processes on the individual vertebrae. Thus, snakes can tie themselves in knots, spin their body vigorously when grabbed by the tail, flatten themselves both vertically and horizontally, and squeeze through holes and cracks that may appear too small for them to get through at all. All snakes can swim (some sea snakes have a flattened tail that allows them to swim much like a fish), many are great climbers with prehensile tails, and others are highly modified for burrowing. The vertebral column in snakes has been divided into four regions (Szyndlar 1984). These regions consist of (1) cervical vertebrae, (2) trunk vertebrae, (3) cloacal

vertebrae, and (4) caudal vertebrae. By far those most generally used in fossil identification are trunk vertebrae from the middle part of the column (see fig. 35). Unfortunately, fossilized ribs, which often show up in Pleistocene and Holocene deposits, are not very useful in the identification of snakes to the specific or even the generic level.

Fig. 35. Eastern Gartersnake vertebra from the Pleistocene epoch in (A) dorsal and (B) ventral views. Illustration by Rosemarie Attilio.

All discoveries of fossil or subfossil remains of amphibians and reptiles in Michigan are especially important because such finds have been relatively few in Michigan compared to those made in nearby states. Potential discoveries of any vertebrate fossil remains should be brought to the attention of professional paleontologists or museum collections curators.

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2

Species Accounts

Checklist of Michigan Amphibians and Reptiles Following is a checklist of the amphibians and reptiles of Michigan. For scientific names down to the family level, I follow Frost (1985) for salamanders and anurans, Ernst and Lovich (2009) for turtles, Estes (1983) for lizards (with the exception that the Squamata is considered an order that contains both lizards and snakes), and Holman (2000) for snakes. For common names of families, I generally follow Frank and Ramus (1995). For genera, species, and subspecies (for both scientific and common names), I generally follow the standardized work of Crother (2008), except for the deviations noted. Where a species is divided into two or more recognized subspecies, those subspecies present in Michigan are listed. I also use traditional (Linnaean) taxonomic groupings (e.g., classes, orders, families), despite a recent trend to abandon these categories in favor of hierarchical phylogenies based on presumed evolutionary relationships (see Vitt and Caldwell 2009, 20–25, for discussion). Note that the taxonomic placement and scientific names of amphibians and reptiles are presently quite unstable, as new studies (particularly those based on

DNA) are published and new arrangements of relationships are proposed on an almost daily basis. In this book and in the following checklist I have attempted to incorporate recent changes for which the acceptance level appears high among herpetologists, but for recent proposed changes that remain controversial, I have chosen to retain more familiar and traditional nomenclature. For example, Frost et al. (2006) offered a greatly revised taxonomy of the amphibians; in this work the authors replaced the familiar generic designations for Michigan’s toads (Bufo) and ranid frogs (Rana) with Anaxyrus and Lithobates, respectively. While this change was accepted by Crother (2008), some respected herpetologists have challenged the rationale for these changes (e.g., Pauly et al. 2009); thus, until this controversy is settled, it seems prudent to use the traditional names. In any case, the taxonomic arrangement and many of the names used here will certainly be modified or superceded in the future. The roman numerals signify the Michigan Regional Landscape Ecosystems (MRLE) distribution (I–IV) of each Michigan form (see fig. 10). An “A” signifies that a species occurs in all four regions.

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The Amphibians and Reptiles of Michigan

CLASS AMPHIBIA Linnaeus 1758—Amphibians ORDER CAUDATA Oppel 1811—Salamanders FAMILY AMBYSTOMATIDAE Hallowell 1858—Mole Salamanders Ambystoma laterale Hallowell 1856—Blue-spotted Salamander—A Ambystoma laterale Hallowell 1856 x Ambystoma jeffersonianum (Green 1827)—Blue-spotted/Jefferson Salamander complex—I Ambystoma maculatum (Shaw 1802)—Spotted Salamander—A Ambystoma opacum (Gravenhorst 1807)—Marbled Salamander—I Ambystoma texanum (Matthes 1855)—Smallmouthed Salamander—I Ambystoma tigrinum tigrinum (Green 1825)—Eastern Tiger Salamander—I, II, III FAMILY PLETHODONTIDAE Gray 1850—Lungless Salamanders Hemidactylium scutatum (Temminck and Schlegel in Von Siebold 1838)—Four-toed Salamander—A Plethodon cinereus (Green 1818)—Eastern Redbacked Salamander—A FAMILY PROTEIDAE Gray 1825—Olms and Waterdogs Necturus maculosus maculosus (Rafinesque 1818)— Common Mudpuppy—A FAMILY SALAMANDRIDAE Gray 1825—Newts and Fire Salamanders Notophthalmus viridescens (Rafinesque 1820)— Eastern Newt: Notophthalmus viridescens louisianensis (Wolterstorff 1914)—Central Newt—A Notophthalmus viridescens viridescens (Rafinesque 1820)—Red-spotted Newt—I FAMILY SIRENIDAE Gray 1825—Sirens Siren intermedia nettingi (Goin 1942)—Western Lesser Siren—I ORDER ANURA Rafinesque 1815—Frogs and Toads Toads: FAMILY BUFONIDAE Gray 1825—True Toads Bufo americanus americanus Holbrook 1836—Eastern American Toad—A Bufo fowleri Hinckley 1882—Fowler’s Toad—I, II

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Frogs: FAMILY HYLIDAE Gray 1825 (1815)—Treefrogs Acris crepitans blanchardi Harper 1947—Blanchard’s Cricket Frog—I, II, ?III Hyla chrysoscelis Cope 1880—Cope’s Gray Treefrog—A Hyla versicolor LeConte 1825—Gray Treefrog—A Pseudacris crucifer crucifer (Wied-Neuwied 1838)— Northern Spring Peeper—A Pseudacris maculata (Agassiz 1850)—Boreal Chorus Frog—IV Pseudacris triseriata (Wied-Neuwied 1838)—Western Chorus Frog—A FAMILY RANIDAE Gray 1825—True Frogs Rana catesbeiana Shaw 1802—American Bullfrog—A Rana clamitans melanota Rafinesque 1820—Northern Green Frog—A Rana palustris LeConte 1825—Pickerel Frog—A Rana pipiens Schreber 1782—Northern Leopard Frog—A Rana septentrionalis Baird 1854—Mink Frog—III, IV Rana sylvatica LeConte 1825—Wood Frog—A CLASS REPTILIA Laurenti 1768—Reptiles ORDER TESTUDINES Batsch 1788—Turtles FAMILY CHELYDRIDAE Gray 1870—Snapping Turtles Chelydra serpentina serpentina (Linnaeus 1758)— Eastern Snapping Turtle—A FAMILY EMYDIDAE Lydekker 1889—New World Pond Turtles Chrysemys picta (Schneider 1783)—Painted Turtle: Chrysemys picta bellii (Gray 1831)—Western Painted Turtle—IV Chrysemys p. marginata (Agassiz 1857)—Midland Painted Turtle—I, II, III Chrysemys picta bellii (Gray 1831) x Chrysemys picta marginata (Agassiz 1857)—III, IV Clemmys guttata (Schneider 1792)—Spotted Turtle—I, II Emydoidea blandingii (Holbrook 1838)—Blanding’s Turtle—A Glyptemys insculpta (LeConte 1830)—Wood Turtle—A Graptemys geographica (Lesueur 1817)—Northern Map Turtle—A Terrapene carolina carolina (Linnaeus 1758)—Eastern Box Turtle—I, II Trachemys scripta elegans (Wied-Neuwied 1838)— Red-eared Slider—I, II

2. Species Accounts



FAMILY KINOSTERNIDAE Baur 1893—American Mud and Musk Turtles Sternotherus odoratus (Latreille 1801)—Eastern Musk Turtle—I, II



FAMILY TRIONYCHIDAE Bell 1828—Softshells Apalone spinifera spinifera (Lesueur 1827)—Eastern Spiny Softshell—I, II



ORDER SQUAMATA Oppel 1811—Lizards, Snakes, and Worm Lizards

Lizards: FAMILY SCINCIDAE Gray 1825—Skinks Plestiodon fasciatus (Linnaeus 1758)—Five-lined Skink—A

FAMILY TEIIDAE Gray 1827—Tegus Aspidoscelis sexlineata (Linnaeus 1766)—Six-lined Racerunner—I

Snakes: FAMILY COLUBRIDAE Oppel 1811—Advanced Snakes Clonophis kirtlandii (Kennicott 1856)—Kirtland’s Snake—I Coluber constrictor foxii (Baird and Girard 1853)— Blue Racer—I, II, III Diadophis punctatus edwardsii (Merrem 1820)— Northern Ring-necked Snake—A Heterodon platirhinos Latreille 1801—Eastern Hog- nosed Snake—I, II, III Lampropeltis triangulum triangulum (Lacépède 1788)—Eastern Milksnake—A

Recent Accounts These accounts include amphibians and reptiles that presently live in Michigan and have been documented by museum specimens, accounts in the scientific literature, and accounts of herpetologists doing recent research in the field. They represent species from the Upper and Lower Peninsulas of Michigan as well as the major Michigan Great Lakes and river islands and the islands in the Lake Michigan Archipelago (Bowen and Gillingham 2004).

Class Amphibia Amphibians may be generally defined as tetrapods (fourlegged animals) that have moist, scaleless glandular skin and, with many exceptions, an unshelled aquatic egg and

Nerodia erythrogaster neglecta (Conant 1949)— Copper-bellied Watersnake—I Nerodia sipedon sipedon (Linnaeus 1758)—Common Watersnake—A Opheodrys vernalis (Harlan 1827)—Smooth Greensnake—A Pantherophis spiloides (Duméril, Bibron, and Duméril 1854)—Central Ratsnake—I, II Pantherophis gloydi (Conant 1940)—Eastern Foxsnake—I, II Pantherophis vulpinus (Baird and Girard 1853)— Western Foxsnake—III, IV Regina septemvittata (Say 1825)—Queen Snake—I, II, III (Bois Blanc Island only) Storeria dekayi (Holbrook 1836)—DeKay’s Brownsnake: Storeria dekayi dekayi (Holbrook 1836)—Northern Brownsnake x Storeria dekayi wrightorum Trapido 1944—Midland Brownsnake—I, II Storeria dekayi wrightorum Trapido 1944—Midland Brownsnake—III, IV Storeria occipitomaculata occipitomaculata (Storer 1839)—Northern Red-bellied Snake—A Thamnophis butleri (Cope 1889)—Butler’s Gartersnake—I, II Thamnophis sauritus septentrionalis Rossman 1963—Northern Ribbonsnake—I, II, III (Bois Blanc Island only) Thamnophis sirtalis sirtalis (Linnaeus 1758)—Eastern Gartersnake—A

FAMILY VIPERIDAE Oppel 1811—Vipers Sistrurus catenatus catenatus (Rafinesque 1818)— Eastern Massasauga—I, II, III (Bois Blanc Island only)

an aquatic larval stage that metamorphoses into an adult that is at least partially terrestrial. Amphibians evolved from fleshy-finned (sarcopterygian, osteolepiform) fishes late in the Devonian period (about 360 million years BP) and as a group reached their maximum diversity during the middle to late Carboniferous period (about 350 million to 290 million years BP). Some ancient amphibians were rather large—some reaching six feet (2 m) in length— flat-bodied creatures that looked like squat, large-headed alligators. Many others were smaller, much like elongated, flat-skulled salamanders, while some were legless, looking superficially like snakes, and one very strange amphibian from Texas (Diplocaulus) had a head shaped like a boomerang. Fossil evidence shows that at least some of

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The Amphibians and Reptiles of Michigan

these laid their eggs in water, had aquatic larval stages, and were at least somewhat terrestrial as adults, just like living amphibians.

FIG. 37. Pedicellate teeth of a frog: (A) crown, (B) pedicel, (C) pedicel with the crown broken off, and (D) new crown emerging from the pedicel. Illustration by the author.

Order Caudata Three amphibian orders—Caudata (salamanders), Anura (frogs and toads), and Gymnophiona (caecilians, which are legless, worm-like creatures native to the tropics)— are lumped together in a group called the Lissamphibia. All the lissamphibians have specialized pedicellate teeth (figs. 36 and 37), which are unique enough to suggest a common ancestry for the three groups.

Family Ambystomatidae

FIG. 36. Pedicellate teeth of a salamander: (A) crown, (B) pedicel, and (C) pedicel with crown broken off. Illustration by the author.

Salamanders are sometimes mistaken for lizards, but salamanders typically have moist, slimy, scaleless skins and lack claws on the toe tips, while lizards have dry, scaly skins and sharp claws on the toes. Salamander bodies wriggle from side to side when they decide to run. Lizards run upright and normally have a stronger set of legs than salamanders. Comparing salamanders and frogs, salamanders have relatively small heads, long bodies with front and back legs of about the same size, and long tails; frogs have very large, flat heads, short bodies with the hind legs much larger than the front, and no tails. Salamanders occur in northern Europe and Asia, North Africa, and the Americas (Frost 1985). The Appalachian region of North America is the world hotspot for salamander species diversity.

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The Ambystomatidae (Mole Salamanders) are stoutbodied as salamanders go. They have rounded heads and prominent costal grooves (grooves aligned with the ribs that encircle the body). They lack nasolabial grooves (slitlike channels that run from the nostril to the upper lip) that characterize the lungless Plethodontidae, another conspicuous group of American salamanders. Transformed ambystomatid adults have lungs. The larvae have broad heads, three pairs of bushy external gills, and conspicuous tail fins that extend onto the back. In some Ambystoma species, the gills (and aquatic habit) may at times be retained into adulthood (a condition called neoteny). Some populations of Ambystoma in southeastern Canada and the north-central and northeastern United States (including Michigan) are of hybrid origin and consist of polyploid individuals that are usually entirely female. This phenomenon is described in more detail in the accounts. The Ambystomatidae presently contains two recognized genera: Ambystoma Tschudi 1838, which occurs in much of North America and extends southward into central Mexico, and Rhyacosiredon Dunn 1928, which occurs only in the mountains of central Mexico (Petranka 1998). This group is collectively known as the mole salamanders because they spend much of their lives in underground burrows. However, many of them do not actually dig their own burrows in the manner of moles but instead enlarge natural holes or the burrows of small animals using their feet and body and head movements.

2. Species Accounts

Ambystoma laterale Hallowell Blue-spotted Salamander (considered to be the “pure form” of this species) Identification The Blue-spotted Salamander is the only Michigan salamander that has pale blue or turquoise spots or flecks on a black or grayish-black body (except for some odd Ambystoma hybrids that will be discussed later). These markings occur on the belly, sides, legs, tail, and often on the back. Ball (1999) measured the total length of 389 female and 53 male Blue-spotted Salamanders from a breeding pond in a wooded lot isolated by cultivation in Washtenaw County in southeastern Michigan. The total length of the females ranged from 48.8 to 172.0 mm (1.92–6.77 in.) with a mean length of 138.1 mm (5.44 in.). The total length of the males ranged from 96.2 to 133.1 mm (3.79–5.24 in.) with a mean length of 118.8 mm (4.68 in.). General Distribution Minton (2001, 57) delineated the range of Ambystoma laterale as “Goose Bay, Labrador, west to Hudson Bay and eastern Manitoba, thence south to northern New Jersey, northern Indiana, and central Minnesota.” Michigan Distribution The Blue-spotted Salamander occurs in every county in the Upper Peninsula. It also occurs on Isle Royale, Drummond Island, Bois Blanc Island, the Charity

Fig. 38. Blue-spotted Salamander (Ambystoma laterale) from Ingham County, Michigan. Photograph by James H. Harding.

Islands, and Washington Island as well as Beaver, Garden, High, and Trout Islands in the Lake Michigan Archipelago (e.g., Carleton et al. 1965; Harding and Holman 1992; Hatt et al. 1948; Long 1993; and Bowen and Gillingham 2004). This species is found generally throughout the Lower Peninsula, but there are several areas where records are oddly lacking. For example, a small gap in its distribution occurs in the northwestern tip of the Lower Peninsula, where there are apparently no records of its presence in the counties of Kalkaska, Grand Traverse, Leelanau, and Antrim. There is also a noteworthy lack of records for many of the counties around Saginaw Bay (with the exception of Huron County) and those that loop around the state’s eastern border from Sanilac County to Monroe County. The absence (or at least low population levels) of A. laterale in these areas may reflect that they are highly cultivated today. On the other hand, the presence of acidic ancient inland dune soil in the counties around Saginaw Bay may be involved in the absence or rarity of A. laterale and other Ambystoma species in the area (Holman 2001b). The lack of A. laterale records from Berrien and Van Buren counties in the southwestern tip of the state is puzzling because these salamanders appear to be relatively common in other counties in southwestern Michigan. Geographic Variation No subspecies of Ambystoma laterale are known. Habitat and Habits Blue-spotted Salamanders differ from most species of Ambystoma in being active on the ground during the warm months of the summer and fall. This has been documented in the Great Lakes states of Ohio (Downs 1989), Michigan (Harding and Holman 1992), Indiana (Minton 2001), and Wisconsin (Vogt 1981). Parmelee (1990) has shown that Ambystoma laterale individuals are unable to dig their own burrows in soil and must instead use either large natural holes or enlarge smaller natural holes with their snout and body. In southern Lower Michigan (MRLE Region I) Ambystoma laterale appears to prefer deciduous hardwood forests. Here they occur mainly in moist beech-maple woodlands, but I have also observed this species where relatively dry oak-hickory forests form the dominant vegetation, mainly at lower elevations

31

The Amphibians and Reptiles of Michigan

where intermittent streams, marshes, ponds, or lakes are nearby. In general, I found the summer and fall “surface” populations beneath rotting logs, other organic surface debris, and trash piles (such as plywood, roofing shingles, rugs, or carpeting). As to Blue-spotted Salamander habitats in other areas of Michigan, Ruthven et al. (1928) reported that small colonies of this species occurred on beaches in marshy places under driftwood and other debris. Incidently, they also state that this species is found under stones. I have never found this species (and very few other amphibians and reptiles) under Michigan rocks, which are mainly pieces of unfriable bedrock transported by the Pleistocene ice sheets. As such, they are usually rounded and have little wriggle space under them. Relative to the habitats of the Blue-spotted Salamander in the Great Lakes basin (which includes several states and the province of Ontario), Harding (1997) reports that Blue-spotted Salamanders inhabit both coniferous and deciduous forests from moist bottoms to dry uplands and that they are perhaps most abundant in moist woodlands with sandy soils. He also points out that they otherwise may be found in a variety of habitats, including open fields and suburban backyards. Varied accounts of specific habitats of Ambystoma laterale in Michigan include the Charity Islands near the mouth of Saginaw Bay, where they were found under debris and decaying boards (Thompson and Thompson 1912); Emmet County, where many individuals were found under boards in the upper part of the Lake Michigan beach from Cecil Bay to Mackinac City (Blanchard 1928a); Gogebic County in the UP, where they were found under logs in lowland areas near small streams (A. T. Evans 1915); Washtenaw County, in the Mud Lake Research Area, where they were most common in hardwood swamp and bog mat associations (Heatwole and Getz 1960); and also in Washtenaw County, where one was found February 25, 1951, hibernating in an ant mound at a depth of 457 to 482 mm (18–19 in.) along with seven species of snakes and two species of frogs excavated at different depths in the mound (Carpenter 1953). Reproduction and Growth Adult Blue-spotted Salamanders breed in a variety of aquatic habitats that are free of fishes. In Michigan,

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seasonal and permanent woodland ponds, including those isolated by cultivation (e.g., Ball 1999), are probably the most common breeding sites in the state. Other general breeding sites for the species as a whole, compiled by Petranka (1998), include such disparate sites as springs in pastures, pools on lakeshores, marshes, roadside ditches, and quarry ponds. Blue-spotted Salamander migrations to breeding ponds occur in late winter or early spring on rainy nights, with males arriving at the breeding sites shortly before females (Petranka 1998). J. C. Ball studied salamanders breeding in five vernal ponds in a woodlot isolated by cultivation in Washtenaw County, Michigan, from 1996 to 2004. Ball (2003) found that Ambystoma laterale had a distinct preference for one of the ponds (Pond 3) in 1997 and 1999. In 1996 many A. laterale were found beneath ice that was as thick as 30 mm (1.18 in.), but evidence of egg laying was not detected (Ball 1998). In the spring of 1997, Ball (1999) did a comprehensive survey of breeding ambystomatid salamanders in all five of the vernal ponds. The first Blue-spotted Salamanders were captured on March 3. The number of captures peaked dramatically from March 21 to 23, and the last capture was April 10. The dramatic peak in captures from about March 21 to 23 undoubtedly reflects the explosive breeding patterns that have been recorded for the species (e.g., Talentino and Landre 1991). The description of general courtship behavior in Ambystoma laterale is condensed here from Kumpf and Yeaton (1932), Petranka (1998), Storez (1969), and Uzzell (1964). The courtship behavior in A. laterale is very similar to that of the closely related species Ambystoma jeffersonianum, with which it sometimes hybridizes. To start the courtship process, male A. laterale move about randomly on the pond bottom until they find other individuals of their species. A prowling male then gently probes the sides of these individuals with his snout. Ultimately the probing is directed only at females. Next the male grabs a female behind her forelegs with his forelegs. This position may be held for more than ten minutes, and during this time span, other males may try to break the pair apart. After amplexus, the male moves forward and rubs his chin from side to side while undulating his body over the female’s back as well as moving his legs in stroking movements along her sides. Some other movements

2. Species Accounts

are sometimes used during this phase of the courtship process (see Petranka 1998). Finally, the male releases the female, moves forward while vibrating his body, and deposits a spermatophore (a jelly-like capsule containing sperm in seminal fluid). The female follows the male as he moves forward depositing from about eight to thirty or more spermatophores on the substrate. Four gelatinous horn-shaped structures at the top of each spermatophore contain the seminal fluid. As the male moves forward depositing spermatophores, the female follows along, picking up seminal fluid from one or more spermatophores with her cloaca. Fertilization thus takes place within the body of the female. In the Great Lakes region, Blue-spotted Salamanders usually lay their eggs within two days of mating. They attach the egg masses to sticks, leaves, rocks, and other underwater objects (Harding 1997). These masses usually consist of about 2 to 8 eggs per mass (Petranka 1998), but in Masschusetts Talentino and Landre (1991) recorded an average of 19 eggs per mass. In Indianapolis, Indiana, Blue-spotted Salamander eggs collected in the field and kept outdoors hatched on April 18 and 19, twenty-two and twenty-three days after their deposition (Minton 2001). In southern Michigan, a large group of females yielded an average of 216 eggs each (Clanton 1934). Petranka (1998) suggests that Ambystoma laterale larvae feed mainly on zooplankton and dipteran larvae, as larvae do in other Ambystoma species. The larval period is relatively short in this species, and A. laterale larvae in Illinois complete their transformation in late June through mid-August after eight to ten weeks (P. W. Smith 1961). Petranka (1998, 66) stated that “the aquatic larval stage probably functions as an ecological bottleneck that sets an upper limit on adult population size.” In a study of thirty-six larval populations of Blue-spotted Salamanders inhabiting pools along the coast of Isle Royale, Van Buskirk and Smith (1991) studied larval density as a factor in the determination of adult population size and health. They found that as many as 158 hatchlings per square meter per pool could exist but that a lower growth rate, lower survival rate, and higher rate of individuals without tails were related to high larval density in both experimental and natural populations. Food limitation was evidently not a factor in the development of these dense populations, but

intraspecific larval aggression was deemed the primary mechanism at work. Wilbur (1977) reported that A. laterale juveniles from Michigan grow rapidly and become mature when they are about two years old. Petranka (1998) suggests that a two-year maturation period is probably typical of the species as a whole. The smallest mature females and males from localities studied by Uzzell (1967a) measured 51 mm (2 in.) and 41 mm (1.6 in.) in snoutto-vent length, respectively. Diet Ruthven et al. (1928) reported that the stomach contents of “a number of specimens” of Ambystoma jeffersonianum (A. laterale) indicated that they fed on earthworms, small crustaceans, and insects. The stomach of one of the specimens was completely filled by a single large click beetle. The digestive tracts of “several” A. laterale, found March 27 in the dunes of northwestern Indiana near Lake Michigan, not far from Tremont, contained beetles and their larvae, centipedes, a roach, and many fragments of unidentified arthropods (Minton 2001). Predation and Defense Rand (1954) described defensive posturing in juveniles and small adults from northern Indiana. If these animals were handled roughly, they elevated their tails vertically, spread and braced their hind limbs, raised their vent area off the ground, lowered their heads, and undulated their tails vigorously as they secreted a white, sticky matter from the tail. Brodie (1977) reported that, depending on which part of the body is disturbed, tail lashing or body coiling occurs. A photograph by E. D. Brodie of A. laterale from Calhoun County, Michigan, in its defensive posture is shown in Petranka (1998, 67, fig. 34). I am not aware of any studies that indicate the reaction of potential predators to this display; specific accounts of predation on Ambystoma laterale are rare. However, Carleton et al. (1965) reported that a Common Watersnake (Nerodia sipedon sipedon) from Garden Island, Michigan, once regurgitated a Blue-spotted Salamander. Interaction with Humans Harding (1997) suggested that Ambystoma laterale is relatively tolerant of selective logging and low-density housing development as long as the critical parts of

33

The Amphibians and Reptiles of Michigan

its habitat remain. Wooded areas with fishless, shallow ponds are essential. Alteration of the hydroperiod, allowing for colonization, or the introduction of fish to a breeding site can have significant impacts on populations. Populations are also threatened by clearcutting of wooded lands and by roads that cut off access to breeding ponds. Roads act to fragment the landscape and increase the risk of road mortality. In addition, the leached hydrocarbons and road salt surface runoff negatively impact water quality in adjacent breeding sites, reducing overall viability and wetland function as amphibian breeding sites. Behavioral Characteristics For the behavioral characteristics of Ambystoma laterale, see the previous sections “Reproduction and Growth” and “Predation and Defense.” Population Health Ambystoma laterale has been listed as a Species of Greatest Conservation Need, and populations appear to be holding their own where intact habitat still exists. General Remarks How common is “common”? If someone were to ask me what the most common Ambystoma species in Michigan is (five species and some hybrids occur), I would say, “Bluespotted Salamanders, of course!” But A. laterale spends the warm days of summer and autumn on the ground surface, not tucked away in a burrow, like the other Ambystoma species that occur in the state. Could not that behavior make them appear to be more common than they actually are? Answering that question is one reason that studies on breeding populations are so valuable. For instance, during the winter-spring salamander breeding event of 1997 reported by Ball (1999) for his five-pond area in southern Michigan, 797 adult Bluespotted Salamanders were caught, whereas 54 adult Spotted Salamanders (Ambystoma maculatum) and only 2 adult Tiger Salamanders (Ambystoma tigrinum) were captured. These numbers help confirm that, at least in this area, Blue-spotted Salamanders are probably the most common Ambystoma species.

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Ambystoma laterale Hallowell 1856 x Ambystoma jeffersonianum (Green 1827) Blue-spotted/Jefferson Salamander Complex (pure forms plus various hybrid complexus) Blue-spotted Salamanders have hybridized with other ambystomatid salamanders in the southern part of Michigan. They have most frequently hybridized with the Jefferson Salamander, yet oddly, pure populations of Jefferson Salamanders are unreported in Michigan (Harding 1997). This situation is certainly an apparent dilemma. The most common hybrid salamander found in Michigan is an all-female polyploid that has two sets of chromosomes from the Blue-spotted Salamander and one set from the Jefferson Salamander. (Such salamanders are called triploids; typical salamanders are diploids, having one set of chromosomes from their mother and one from their father.) These all-female hybrids are found throughout most of the lower half of the Lower Peninsula. Less commonly, polyploids with one set of Blue-spotted Salamander chromosomes and two or three sets of Jefferson chromosomes are found (known from only two sites in Michigan). Hybrid salamanders are larger (4.7–6.8 in. in total length) and grayer than the smaller dark blue or black Blue-spotted Salamander (total length 3.8–5.2 in.) (Ball 1999). Compared to the hybrids, Blue-spotted Salamanders also have more bluish white flecking, especially on their dorsal surface. Relative to reproduction in Michigan, Blue-spotted Salamanders and the polyploids arrive at their breeding ponds from mid-March to mid-April, soon after the snow and ice has melted. Rain will increase migration to these ponds but is not a requirement. Soon after their arrival at the ponds, females will attract male Bluespotted Salamanders, and mating will follow (Kumpf and Yeaton 1932; Weller 1986). Some female hybrids may pick up sperm packets without going through the courtship sequence with a male salamander (unpublished manuscript by W. Clanton discussed in Wilbur 1972), which may explain why some of the hybrid salamanders contain chromosomes from other species, such as the Small-mouthed Salamander and Tiger Salamander. Egg laying begins about one to two days later (Wilbur 1977). Hybrid salamanders lay fewer, larger

2. Species Accounts

eggs compared to the Blue-spotted Salamanders. Eggs are often laid singly or in small clumps on twigs or vegetation (Clanton 1934; Uzzell 1964). Less than 20 percent of the hydrid eggs found in ponds are fertile. Infertile eggs tend to be light in color, whereas the fertile eggs are darkly pigmented. Many of the female hybrids fail to mate with a male Blue-spotted Salamander, but the eggs are deposited anyway. Fertile eggs hatch in fifteen to eighteen days, and larvae metamorphose from the middle of July to early August in Lower Michigan (Wilbur 1971). Hybrid larvae typically metamorphose about a week later than Blue-spotted Salamander larvae (Uzzell 1964; Wilbur 1971; Lowcock 1994). The diet of hybrids is similar to that of Blue-spotted Salamander larvae and is composed primarily of aquatic worms, water fleas, fairy shrimp, and larval midges (Manion and Cory 1952; Wilbur 1971). The diet of the adult salamanders is composed primarily of snails, beetles, earthworms, small crustaceans, and insect larvae (Ruthven et al. 1928; Bellocq et al. 2000). The predators of hybrid larvae are the same as those of Blue-spotted Salamander larvae; both are preyed upon by dragonfly larvae, aquatic beetles, larger Tiger Salamander larvae, the giant water bug, Eastern Newts, and leeches. Female hybrids seem to require male sperm to activate their eggs. In the phenomenon called gynogenesis, a sperm penetrating the egg is sufficient for the egg to develop into a larval salamander. Fertilization does not actually occur, and the male’s chromosomes are discarded from the developing egg (Spolsky et al. 1992). Although gynogenesis is the most common form of reproduction in these unisexual (all-female) populations, it has recently been discovered that they may occasionally use normal sexual reproduction and incorporate male chromosomes into their embryos (Ramsden 2008). Research on the natural history and biogeography of salamanders of the Blue-spotted/Jefferson Salamander hybrid complex is ongoing. For instance, hybrids once thought to be isolated on islands in Lake Erie (Kraus 1985) have recently been discovered in Cass County, Michigan (James C. Ball, pers. comm.). The Blue-spotted Salamander and the Jefferson Salamander were often confused with each other and were not clearly separated until the middle of the twentieth century. Clanton (1934) noted that a darker, smaller form near Ann Arbor, Michigan, was different from a larger form from central Pennsylvania. He noted the larger form had much larger

sperm packets than the males from Ann Arbor. He also noticed that females of the smaller form produced many more eggs and of a smaller size than did the larger form. Based on these and other observations, he suggested that two forms or races existed in the Jefferson Salamander. He also observed that females greatly outnumbered males in the same breeding pond in Ann Arbor. He suggested that the larger, lighter form was a hybrid between the two races, and that this hybrid was also present in populations of the larger, more southern, Pennsylvania race. Minton (1954) compared the larger form from southern Indiana to the smaller, darker, and more northern forms from the Indiana Dunes, located on the southern shore of Lake Michigan. Based on careful morphological studies of these two salamanders, he recognized the small, darker form as the Blue-spotted Salamander, first discovered by Hallowell almost a hundred years earlier, and the larger specimens as the Jefferson Salamander. Minton also identified possible hybrids between the two species and suggested that these all-female hybrids may compete for males from one of the two species. Uzzell (1964), in his landmark study of this complex, suggested that these two species hybridize, yielding two different hybrid species—the Silvery Salamander Ambystoma platineum (Uzzell 1967b) and Tremblay’s Salamander Ambystoma tremblayi (Uzzell 1967c). Species recognition of these two hybrids is currently not accepted because of the number and variety of ambystomatid hybrids that are now known to exist. Thus, only the common and scientific names in the heading of this account are officially recognized (Lazell 1971; Lowcock et al. 1987; Crother 2008). Kraus and Miyamoto (1990) and more recently Bogart (2003) and Robertson et al. (2006) studied the origin of the hybrids by looking at the mitochondrial DNA. They proposed that the Streamside Salamander, Ambystoma barbouri Kraus and Petranka 1989, was the original female ancestor to all of the hybrid salamanders and that the Ambystoma polyploidy complex had a fairly recent origin, perhaps within the last 25,000 years. Other polyploid salamanders in Michigan with chromosomes from Blue-spotted, Jefferson, Smallmouthed, or Tiger Salamanders have two, three, and four sets of chromosomes. These hybrids can be found in many Michigan counties, especially those bordering Indiana and Ohio (Kraus 1985).

35

The Amphibians and Reptiles of Michigan

Ambystoma maculatum (Shaw 1802) Spotted Salamander Identification The Spotted Salamander is a beautiful species that is easy to identify in Michigan because it is the only salamander in the state with a black or dark grayish-brown body and tail with two irregular rows of roundish yellow spots running from the back of the head onto the tail. The spots on the head proper are often orange. In the Great Lakes region, Harding (1997) noted that this species sometimes has tan, grayishwhite, or cream-colored spots on the body and that rarely a specimen may be virtually spotless. The belly is unspotted and may be gray or purplish brown. During the breeding season, males have strikingly swollen vents. Ball (1999) measured ten female and forty male Spotted Salamanders from breeding ponds in a woodlot isolated by cultivation in Washtenaw County in southeastern Michigan. The total length of females ranged from 136.1 to 177.0 mm (5.36–6.97 in.) with a mean length of 159.1 mm (6.26 in.). The total length of males ranged from 118.4 to 176.6 mm (4.66–6.95 in.) with a mean length of 152.4 mm (6.00 in.). General Distribution For the distribution of the Spotted Salamander, I follow Frost (1985, 556), who delineates the range of Ambystoma maculatum as “Nova Scotia and Gaspe Peninsula west to

FIG. 39. Spotted Salamander (Ambystoma maculatum) from Michigan. Photograph by James H. Harding.

36

central Ontario in Canada, and south through the eastern USA to southern Georgia and west to Louisiana and eastern Texas.” Michigan Distribution The Spotted Salamander is generally considered to be of statewide occurrence in Michigan. It has been found in every county in the Upper Peninsula. It also occurs on Isle Royale, Drummond Island, Bois Blanc Island, and Washington Island as well as Beaver and North and South Manitou Islands in the Lake Michigan Archipelago. Surprisingly, this species lacks documented records for a number of counties in the Lower Peninsula. Although Ambystoma maculatum is moderately well represented in about the upper third of the Lower Peninsula, where records are available from Charlevoix, Cheyboygan, Presque Isle, Antrim, Montmorency, Kalkaska, Crawford, and Alcona counties, records are noticeably absent in the central part of the Lower Peninsula and the Midland–Saginaw Bay and thumb areas. These gaps in the record of A. maculatum may be caused in part from a lack of scientific collecting in some of these counties, but human disturbances, such as intensive cultivation, and natural differences, such as soil structure or absence of mature hardwood forests, may be important factors in the Michigan distribution of this species. Geographic Variation No Spotted Salamander subspecies are presently recognized (Crother 2008). Geographic variation in the color of body spots is discussed in the identification section of this account. The presence or absence of orange spots on the head of this species is often variable in local populations. This feature appears to be inconsistent across the range of this species (Petranka 1998). Long (1993) reported a specimen of A. maculatum from Washington Island that had greenish-yellow spots. Phillips (1994) discovered that many populations of A. maculatum in the Ozark region were genetically uniform, a phenomenon that may indicate that the species only recently invaded that area. Habitat and Habits In Michigan, Spotted Salamanders inhabit moist deciduous woodlands in the vicinity of vernal ponds but avoid cut-over forests and those that are likely to flood

2. Species Accounts

(Harding and Holman 1992). In other regions, the species occasionally occurs in upland forests and even in mountainous regions where suitable breeding sites are present (Thompson and Gates 1982). These animals spend much more time underground in the warmer months of summer and fall than Ambystoma laterale. For example, adults in a Kentucky nonmigratory population were found to spend 72 percent of their time beneath the ground surface, 21 percent under rotting logs, and 7 percent beneath wet leaf litter (Kleeberger and Werner 1983). The same authors found that migratory populations moved an average of 14 m (45.9 ft.) over an interval of six to seven weeks and had home ranges of about 10 square meters (108 sq. ft.). In the spring, a small number of Spotted Salamanders may be found beneath logs on the forest floor, but they go underground when summer comes (Parmelee 1993). According to Gordon (1968) and Semlitsch (1983), these salamanders appear to be incapable of actively digging burrows, but they are able to enlarge existing crevices and holes and to live as deep as 1.3 m (4.26 ft.) underground. This species was commonly found in early spring under rotting logs in the Baker Woodlot on the MSU campus. James C. Ball (pers. comm.) reported in 2004 that A. maculatum, along with A. laterale, now appears to be extirpated from this isolated habitat; however, two developing eggs masses found in the spring of 2007 indicated the potential for a small but viable population to still persist (David Mifsud, pers. comm.). Reproduction and Growth Spotted Salamanders breed in several types of aquatic habitats that are fish free. In Michigan, vernal ponds in moist woodlands are probably most often used for breeding. Other breeding sites for the species as a whole, noted by Petranka (1998), include swamps, roadside ditches, and flooded tire tracks as well as permanent ponds. A New York population even bred in a large but fish-free lake (Bahret 1996). Ball (1999), Blanchard (1930), and Husting (1965) noted that A. maculatum breeds in March and April in Michigan. In five vernal ponds in an isolated woodlot in Washtenaw County, Michigan, studied by J. C. Ball in 1997, the first Spotted Salamanders were captured on March 17; the number of captures peaked dramatically on one day, March 31, and the last A. maculatum (one individual) was taken on April

7. The peak on March 31 near the end of the breeding season indicates an explosive breeding pattern also shared by A. laterale in the same ponds (Ball 1999). Husting (1965) studied marked individuals of A. maculatum at a single breeding site near Ann Arbor for five consecutive breeding migrations. He presented dates for the beginning, peak, and duration of migration (in days) for the species. In 1959 the first individual seen was on March 25, the last peak was on April 5, and the duration of the migration was eleven days. In 1960 the first one seen was on March 29, the last peak was April 11, and the duration of the migration was thirteen days. In 1961 the pattern was different, as the first salamander seen was on March 4, the last peak was April 6, and the duration of the migration was twenty-nine days. In 1962 the first seen was on March 28, the last peak was on April 13, and the duration of the migration was sixteen days. In 1963 the first salamander seen was on March 25, the last peak was on April 2, and the duration of the migration was nine days. Husting (1965) also found during this study that male survivorship was higher than that of the females. Moreover, breeding frequency was irregular, as each year large numbers of males and females were found that were unmarked. A small number of marked individuals bred nearly every year, but most skipped a year or two before returning to breed. Relative to postbreeding migration by Ambystoma maculatum in Michigan, individuals from a breeding pond in the C. H. McCormick Experimental Forest in Marquette in the Upper Peninsula moved from 157 to 249 m (515.0–816.7 ft.), with a mean of 192 m (629.8 ft.), from the pond after breeding during the 1977 and 1978 seasons (Kleeberger and Werner 1983). At this site, adults stopped migrating and became sedentary by the first of June. The following account of courtship in A. maculatum is mainly condensed from Arnold (1977). When courting, the male circles around the female, making contact with her with his snout, swinging his head back and forth over the top of her body, and lifting his head under her chin. The female turns her body and pushes the male with her snout whenever he makes contact with her. After this, the male moves away, frequently contacting the substrate with his vent, and soon deposits a spermatophore, either on the bottom of the pond or on another spermatophore. During the placement of the

37

The Amphibians and Reptiles of Michigan

spermatophore, the male arches his body and undulates his tail at the level of the substrate. Then he moves forward, and if another spermatophore is encountered along the way, he puts another of his spermatophores on top of it. Otherwise he returns to the female and repeats the previous courtship before putting down additional spermatophores. The female searches for spermatophores by moving her back feet from side to side as she moves slowly forward. When a spermatophore is located, she squats on it and removes the seminal fluid with the lips of her cloaca. As the female leaves the spermatophore, she arches the base of her tail. The female usually mounts about fifteen to twenty spermatophores before the courtship process is over. Males produce about forty spermatophores during their first courtship of the season. Males may court again in the same season, but over the entire season they probably produce less than one hundred spermatophores. Ambystoma maculatum spermatophores are about 6 to 8 mm (.24–.31 in.) tall with a base that is about 6 to 9 mm (.24–.35 in.) in diameter at its widest dimension. The spermatophores have a four-pronged, concave summit that carries the seminal fluid. Females begin to deposit their eggs generally two or three days after mating. In Michigan these eggs are in masses and are usually attached to submerged sticks or plant stems (Harding and Holman 1992). The egg masses are relatively stiff and will often retain their shape when taken out of the water, unlike the less dense egg masses of related species. In Ambystoma maculatum the outer jelly membrane that surrounds the individual eggs is often colonized by a symbiotic unicellular green alga (Oophila amblystomatis). This often gives a greenish tint to the egg masses. The alga presumably increases the oxygen supply to the embryos, especially those in the internal part of the mass that get less oxygen by diffusion from the water. Needless to say, the alga benefits from the carbon dioxide produced by the growing larvae. The mean egg clutch size of A. maculatum is rather similar throughout its range. In Michigan a mean of 172 ova occurred in ten females (Wilbur 1977). The Spotted Salamander has a relatively long incubation period that normally lasts from 4 to 7 weeks (Petranka 1998). A study at an Ohio site by Brodman (1995) showed that A. maculatum had a mean incubation period of 7.14 weeks, 3 weeks longer than A. jeffersonianum, which laid its eggs

38

at the same time. This longer incubation may give the latter species an advantage in its pursuit of available ecological resources. In Massachusetts, Talentino and Landre (1991) showed that A. laterale, a very close relative of A. jeffersonianum, had a faster development rate, hatching nine to ten days before A. maculatum. Embryonic mortality is highly variable in A. maculatum both within and among ponds (Petranka 1998). In an Ohio population, annual embryonic mortality was 28 to 40 percent, independent of egg mass size (Brodman 1995). Small microinvertebrates are the staple diet of A. maculatum larvae of all sizes, and they eat a broader and larger variety of prey as their mouths enlarge with growth. Most larvae of this species transform within two to four months after hatching. In a natural pond in southern Michigan, A. maculatum transformed in mid-August after thirteen weeks of growth (Dempster 1930). In dry years, ponds sometimes dry up before the larvae metamorphose, as noted by Stangel (1988) in Massachusetts. A. maculatum larvae may be very aggressive to one another in aquaria and will bite or even eat one another in such situations. Petranka (1998) reported that Spotted Salamander larvae captured in the field are often missing their tail tips, possibly reflecting aggressive behavior between members of this species. Newly transformed A. maculatum exit the breeding sites within several weeks and move into the surrounding woods during rains. These metamorphs measure from about 36 to 40 mm (about 1.4–1.6 in.) in snout-to-vent length in Massachusetts (Hardy 1952) and about 50 mm (1.97 in.) in total length in Maryland (Shoop 1974). Sometimes the metamorphs burrow into mud near the margin of the breeding pond, and if there is a long period without rain, they may die of dessication (Shoop 1974). Juveniles that do successfully make it into the woodlands are thought to spend most of their time in burrows, not returning to the breeding ponds until they become sexually mature. In Michigan, males reach sexual maturity after two to three years and females after three to five years (Wilbur 1977). As to longevity, most A. maculatum in a Quebec population ranged from two to eighteen years old, with some living to be thirty-two years old (Flageole and Leclair 1992). Spotted Salamanders may live to be twenty-two to twenty-five years old in captivity (P. H. Pope 1928, 1937).

2. Species Accounts

Diet The diet of adult Ambystoma maculatum consists mainly of invertebrates living on the woodland floor. Apparently A. maculatum does not feed during the breeding season (Smallwood 1928). C. H. Pope (1944) reported that, based on about forty stomach content analyses, A. maculatum feeds on earthworms, centipedes, millipedes, snails, slugs, spiders, beetles, ants, and other adult insects and some insect larvae. He also mentioned that larvae have been known to eat waterbugs, water-boatmen, and even tiny fish. Ruthven et al. (1928) reported that Michigan A. maculatum feed upon worms, beetles, and other insects. Predation and Defense The tough outer coat of Spotted Salamander egg masses serves to protect the eggs from predators as well as prevent dessication when ponds recede during periods of drought (Nyman 1987). Petranka (1998) reported that adult Red-spotted Newts, Wood Frog tadpoles, caddisfly larvae, and midge larvae prey upon the eggs and embryos. Larvae are consumed by predators such as aquatic insects, fishes, and other Ambystoma larvae. Adult Spotted Salamanders produce skin secretions that ward off reptile, bird, and mammal predators. Its bright spots are assumed to function as a warning to would-be predators. Ambystoma maculatum adults that are attacked by Gartersnakes or other similar predators often secrete noxious chemicals from the tail that ward off attacks (Petranka 1998). Dodd (1977) reported that attacks made on A. maculatum by Smooth Earthsnakes (Virginia valeriae) will cause the salamander to arch its back and bite. Brodie (1977) mentions that Spotted Salamanders, among other ambystomatid salamanders, may use a “head-down, butting” posture that may protect the head. Brodie et al. (1979) reported that when attacked by shrews of the genus Blarina, A. maculatum lashes with its tail if attacked from the rear or butts with its head if attacked from the front. Interaction with Humans C. H. Pope (1944, 40) related that “the larval spotted salamander has long been standard material for workers in embryology and other branches of zoology, thousands being sacrificed annually on the altar of experimental science.” From time to time, Spotted Salamanders in

the Great Lakes region are collected for the biological supply and pet trade and are usually trapped or caught with a seine at their breeding ponds (Harding 1997). Obviously, area populations would be very negatively affected if these collections were focused on a few scarce breeding sites. Harding also mentioned that acid rain may be a threat to Ambystoma maculatum, even though the sensitivity of their eggs and larvae to pond acidification appears to vary between populations. Roads, road salt, and leaching of hydrocarbons into wetlands can have a significant impact on migration, breeding, and development of larvae. Altered hydroperiod resulting from land development may lead to insufficient water levels and loss of recruitment from breeding ponds. The future of A. maculatum is ultimately tied to the availability of relatively undisturbed woodlands and nearby breeding ponds. Any human endeavor that opens the forest canopy (such as selective logging) may reduce the humidity of the site, which reduces the possibility of survival in Spotted Salamanders. Colonization of invasive herbaceous and woody plants—such as garlic mustard, common buckthorn, honeysuckle, and autumn olive— reduce habitat quality and have been shown to negatively impact A. maculatum populations. Moreover, roads between woodland situations and salamander breeding sites can lead to the death of many individuals moving between the two seasonal habitats. Behavioral Characteristics See the sections “Reproduction and Growth” and “Predation and Defense” for descriptions of A. maculatum behavior. Population Health Spotted Salamanders are recognized as a Species of Greatest Conservation Need in Michigan, but anecdotal reports suggest local population declines. For a time, nearly all the inquiries we received at the MSU Museum requesting help in identifying ambystomatid salamanders pertained to Blue-spotted Salamanders. This latter species seems more tolerant of fragmented, cut-over woodland habitats than does the Spotted Salamander, and it is likely that in the more intensively developed parts of the state, Blue-spotted Salamanders may persist while Spotted Salamander numbers fall.

39

The Amphibians and Reptiles of Michigan

General Remarks C. H. Pope (1944, 38), referring to Spotted Salamanders, stated that “not infrequently, individuals tumble into cellars where they cause considerable concern because of their ‘poisonous’ colors. Needless to say, they are entirely harmless to man.”

Ambystoma opacum (Gravenhorst 1807) Marbled Salamander Identification The Marbled Salamander is another beautiful Ambystoma species that may easily be identified by its short, thick-bodied shape and striking color pattern. The background color is black or brownish black. White or gray markings usually occur as bands across the head and back, and sometimes these merge into an irregular stripe along the side of the back and neck. Black and white bands occur on the tail. The belly may be either black or brown, occasionally with lighter speckles. As to sexual dimorphism, males have pure white dorsal markings, whereas the light markings tend to be gray on females. The vent of the male is more swollen than that of the female, especially during the breeding season. Harding (1997) gave the adult length of this species in the Great Lakes region as 85 to 127 mm (3.3–5.0 in.). General Distribution The Marbled Salamander occurs from New Hampshire and central Massachusetts southward to northern Florida, westward through southeastern New York to the region of Lake Michigan, and southward through the Mississippi River basin to eastern Oklahoma and eastern Texas (Frost 1985). Three apparently disjunct populations occur in the Great Lakes region: one near the southeastern shore of Lake Michigan in northwestern Indiana and southwestern Michigan, another in northeastern Indiana and northwestern Ohio, and one in northeastern Ohio and northwestern Pennsylvania. Michigan Distribution The Marbled Salamander was unknown in Michigan until July 18, 1950, when an adult was taken from under a log 2.5 miles north of Buchanan in Berrien County, the most southwestern county in Michigan (Walley and

40

Smith 1951). Additional specimens were later found in Van Buren and Allegan counties, but apparently none have been reported since 1989 (see the Michigan Natural Features Inventory website). All three of these adjoining counties are bordered on the west by Lake Michigan. The Marbled Salamanders of southwestern Michigan, along with the isolated population of this species in adjacent northwestern Indiana, presumably represent small relict populations (defined as a remnant of a formerly more widespread animal population). Geographic Variation The nomenclature of Ambystoma opacum has been stable for many decades, and no subspecies are currently recognized (Crother 2008). Petranka (1998) points out that the color pattern of this species is variable; thus, this feature does not lend itself to the definition of species, subspecies, or even individual populations. Habitat and Habits Marbled Salamanders occur most often in moist lowland forests but are sometimes found on rocky hillsides as well as drier wooded ridges (Harding 1997). Most of their time is spent beneath logs, rocks, and leaf litter or below the ground surface in the tunnels of small mammals. They are seldom seen outside of the fall breeding season. Compared to other Ambystoma in Michigan, Ambystoma opacum is the most tolerant of dry conditions. Marbled Salamanders seem unable to swim and reportedly will drown if submerged in water (Harding 1997). Reproduction and Growth Unfortunately, because of the small numbers of Ambystoma opacum actually observed in the wild in Michigan, little or nothing is known about the reproduction and growth of this interesting species within the state. Fowler (1991, 9) noted that “unlike most other species of Ambystoma— especially those in the eastern United States that lay their eggs in water in the early spring—the Marbled Salamander lays its eggs in the fall on land. By doing so, it avoids competition with such species as the Bluespotted Salamander (Ambystoma laterale) and the Spotted Salamander (Ambystoma maculatum), which are found in the same general area and which breed in the spring.” Adult Marbled Salamanders make their nests along the margins of ponds that are in the process of drying

2. Species Accounts

Fig. 40. Marbled Salamander (Ambystoma opacum) from Pennsylvania. Photograph by James H. Harding.

up or right in the beds of ponds that have already dried up. Adults in the population begin to move toward the breeding sites in the latter part of summer or early fall. They tend to move at night while it is raining. It was once thought that mating occurred at the nesting site, but Krenz and Scott (1994) provided evidence that males often court females before they reach the nesting site. Adults in northern populations of Ambystoma opacum tend to mate earlier than those in southern populations. Harding (1997) stated that Marbled Salamanders breed from late September through October in the Great Lakes region. Breeding in October or November has been observed in Alabama, Georgia, southern Illinois, Louisiana, Mississippi, North Carolina, South Carolina, and Tennessee (Petranka 1998). Noble and Brady (1933) stated that males show up at breeding sites from a few days to more than two weeks before the females arrive. In South Carolina, 64 percent of the males enter a breeding site before the females show up (Krenz and Scott 1994). The following description of courtship is condensed from Arnold (1977), Bishop (1941), Noble and Brady (1933), and Petranka (1998). Natural courtship has presumably never been observed in Michigan. Courtship begins when a male begins to move around quickly and nudge and lift other males and females. This primary male concentrates this effort on the cloacal region and tail. This activates other males, which start butting and

lifting other individuals, often both males and females. Females frequently react to these male movements by nudging the cloacal region of males. Moreover, when both sexes finally pair up, they often move around in a circle nudging each other’s cloacae. The male finally moves along the female’s body and, while raising his body and undulating his tail, puts a spermatophore on the ground. If the female responds properly, she puts her chin and body over the spermatophore while the male leads her forward. The female then puts her cloaca over the sperm cap and picks up the seminal fluid from the top of the spermatophore. Occasionally a female, rather than following a male forward, noses about until she finds a spermatophore and picks up the seminal fluid. Spermatophores are either multiple or single in Marbled Salamanders. Multiple spermatophores are produced when the male puts one spermatophore on top of another. This behavior covers the sperm of rival males and undoubtedly represents a form of competition between males. When mating is finished, the female Ambystoma opacum finds a site in the dried or partially dried bed of a temporary pond or ditch and digs a shallow nest. These nests are oblong or ovoid in shape and formed in the soil beneath leaf litter or other surface cover (Noble and Brady 1933). The females lay their eggs singly within the nests and then coil around their clutches of eggs, occasionally moving about and turning the eggs. Females

41

The Amphibians and Reptiles of Michigan

sometimes lay their eggs communally, seemingly in places where suitable nest habitat is scarce. In northern areas, such as Michigan, the brooding time is short because of the early onset of severe weather, and this may be one reason this species is so rare in the state. Females generally brood their eggs until they are inundated, though nests are often found without an attending female (Petranka 1998). Ambystoma opacum embryos are capable of hatching between nine and fifteen days after the eggs are deposited, but they do not hatch until the ponds are reflooded (Kaplan and Crump 1978; W. King 1935). Petranka et al. (1982) found that hatching occurs when the oxygen in the eggs becomes too depleted to meet the metabolic needs of the embryos, which then release digestive enzymes from hatching glands on their snouts. These enzymes dissolve the egg capsule and allow the escape of the larvae. Because the timing of hatching is environmentally induced, the size of the hatchlings is variable. Larval A. opacum grow quickly as the water gets warmer with the onset of spring. Scott (1990), in a study in South Carolina using “field enclosures” in natural ponds, found that Marbled Salamander larvae in high-density populations grew more slowly, were smaller at metamorphosis, had a more extended larval period, and had a lower survival rate than larvae that lived in low-density populations. Metamorphosis in Michigan probably would occur in May or June. No growth and age studies have been done on A. opacum in Michigan. C. H. Pope (1944) stated that hatchling A. opacum are not uniform in size and development because the time that they spend in eggs is variable. He stated that .75 inch (about 19 mm) is the average total length at hatching. Pope thought the length at maturity and transformation was 2.5 to 3 inches (about 64–76 mm). Bishop (1941) estimated that in South Carolina maturity in Marbled Salamanders is reached fifteen to seventeen months after transformation. He stated that the average adult total length is 4 inches (about 102 mm) and that the maximum length is 4.75 inches (about 121 mm). Scott (1994) reported that adults of the species return to breed for the first time when they are one to five years old. Diet Much more information is available about the diet of larval A. opacum than about the food habits of

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metamorphs and adults. Harding and Holman (1992) reported that Marbled Salamanders eat small invertebrates such as insects, earthworms, slugs, and snails. Based on a compiled list of references, Petranka (1998) reported that newly hatched larvae begin feeding on zooplankton almost immediately. Small larvae feed mainly on cladocerans, copepods, and ostracods, but aquatic insects, isopods, mites, snails, and oligochaetes are also taken. Large A. opacum larvae eat the eggs and larvae of other amphibians as well as caterpillars that fall into the water from overhanging trees. They also feed on Spotted Salamander larvae and chew the legs and tails of other Marbled Salamander larvae but continue to feed on zooplankton as well. Predation and Defense Petranka (1998, 95) stated that “marbled salamanders are undoubtedly preyed upon by owls, raccoons, skunks, snakes, and other woodland predators.” Liner (1954) reported that a Northern Ribbonsnake (Thamnophis sauritus) regurgitated two metamorph A. opacum. When adult Marbled Salamanders are attacked or otherwise significantly bothered, they secrete a noxious milky fluid from glands along the tail that tends to repel predators. A defensive posture that consists of lowering the head, raising the rear limbs, and lashing the tail at a predator or presumed predator often goes along with this (Brodie 1977; DiGiovanni and Brodie 1981); moreover, females on the nest will often posture when they are first uncovered. Interaction with Humans Fowler (1991) mentioned that the eggs and larvae of Marbled Salamanders are used for research in biological laboratories. It has been suggested that A. opacum may have been introduced into Michigan by humans. However, a strong case can be made that the species occurs as a natural relict population in Michigan because the three southwestern counties where they have been found are contiguous with the relict population that occurs in northwestern Indiana. The greatest threat to Marbled Salamanders in Michigan or anywhere else is the loss of bottomland hardwood forests and the vernal ponds that are associated with them. Petranka (1998, 96) stated that “thousands of local populations of marbled salamanders have already been eliminated by habitat loss, and more will be lost in the future.”

2. Species Accounts

He further suggested that landowners who wish to provide breeding sites for these salamanders (and other amphibians as well) can do so by making artificial vernal ponds (see Biebighauser, n.d.). Behavioral Characteristics Ducey (1989) discovered that resident A. opacum often bite and engage in threat posturing during their first meeting with members of the same species. He also found out, however, that if these animals were kept together for eight days, they would stop avoiding one another. Moreover, in some cases they would also share the same tunnels. Ducey and Heuer (1991) reported that adult Marbled Salamanders are more likely to be aggressive to one another when their food supply is meager, and that this suggests that aggressive behavior might also be associated with the defense of feeding areas. Population Health Field studies are needed to determine the status of this cryptic species in Michigan. Marbled Salamanders are presently listed as Threatened and by law “shall not be taken or possessed” except as authorized by the director of the MDNR. General Remarks The Marbled Salamander is one of the rarest salamanders recorded in Michigan and has not been documented in more than two decades. Any sightings of this salamander should be reported to the Michigan Herp Atlas Project at the MDNR for verification and inclusion in the database. Photo documentation is important, but keep in mind that individual animals cannot be “taken or possessed” without permission from the MDNR.

Ambystoma texanum (Matthes 1855) Small-mouthed Salamander Identification Compared to other ambystomatid salamanders in Michigan, this species has a relatively small head (which looks a little swollen behind the eyes) and a short, blunt snout. This animal is the least colorful of the five species of Ambystoma in Michigan, with its background color ranging from light gray

to brownish gray to black. This background is overlain with light gray speckles or lichen-like splotches, mainly on the sides of the animal. The belly is not as strongly speckled. Males have very swollen vents during the breeding season. Harding (1997) reported that in the Great Lakes region, the adult total length ranges from 110 to 178 mm (4.3–7.0 in.).

Fig. 41. Small-mouthed Salamander (Ambystoma texanum). Photograph by James H. Harding.

General Distribution The general distribution of Ambystoma texanum is mainly taken from Frost (1985) but is slightly modified to include Michigan. The distribution of Ambystoma texanum in the United States is from southeastern Michigan and eastern Ohio west to southern Iowa and south to eastern Texas, Louisiana, Mississippi, and northwestern Alabama. In Canada, Small-mouthed Salamanders are found on Pelee Island in Lake Erie (southern Ontario), and hybrids between A. texanum and A. laterale are reported from the nearby mainland (MacCulloch 2002). Michigan Distribution The Small-mouthed Salamander is known in Michigan from only five counties in the southeastern part of the state. These are Hillsdale, Monroe, Washtenaw, Wayne, and Livingston counties. (The Michigan Natural Features Inventory includes only the first four counties.) This population is not a relict, as it is contiguous with populations in northern Ohio (Harding 1997, 68, map).

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The Amphibians and Reptiles of Michigan

Geographic Variation Populations that were previously recognized as Ambystoma texanum from the Ohio drainage in central Kentucky, southeastern Indiana, and southwestern Ohio (see Minton 2001, 66, map) are now recognized as a separate species, the Streamside Salamander (Ambystoma barbouri), by Kraus and Petranka (1989). Minton (2001, 65) stated that “for the field biologist, this species [the Streamside Salamander] is morphologically identical with the Smallmouth Salamander; there are minor differences in the teeth and maxillary bones. However, its habitat and reproductive biology are significantly different.” The Streamside Salamander lives in hilly upland situations, is found under rocks and logs even during the warm months, and is unique in the genus Ambystoma in that it breeds in small rocky streams. The amount of gray speckling varies quite a bit among local populations of A. texanum, and populations in the southwestern portion of their range tend to be more heavily speckled than those in the north (Petranka 1998), but no subspecies are recognized. Habitat and Habit Harding and Holman (1992, 36) stated that “moist hardwood forests with vernal ponds are the preferred habitat for this species in Michigan. They often remain in lowland areas near the breeding ponds and spend much time underground in crayfish or rodent burrows or beneath decaying logs.” Relative to Ambystoma texanum habitats in the Great Lakes region, Harding (1997) pointed out that Small-mouthed Salamanders are most abundant in lowland floodplain woods but that they also occur where the forest cover has been fragmented or mostly removed, and they may even be found in open habitats, such as farmland and prairie. Minton (2001) reported that wooded bottoms along large streams are the best habitat for A. texanum in Indiana. He also pointed out that this species could be found in many other situations where some forest cover and temporary shallow water is present, but that he had not found specimens where the soil is very sandy. Minton stated that Small-mouthed Salamanders frequently take refuge in crayfish burrows, and that being normally fossorial (or adapted for digging) they are often plowed up. Finally, referring again to Indiana, he pointed out that this species persists longer than most salamanders can in suburban and intensely farmed areas.

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Relative to the species as a whole, populations are considered to be most abundant in bottomland forests and associated wetlands of floodplains or adjoining floodplains (Bragg 1949; Downs 1989; Petranka 1982; and Strecker and Williams 1928). In the western part of the range of this species, adults have been collected in upland ponds, sluggish streams in prairies, and in oakhickory-pine forests in the Ouachita Uplift (Bragg 1949; Collins 1993). Reproduction and Growth In the species as a whole, adults breed in still waters that seasonally become dry, including woodland ponds (usually low-lying hardwood ponds in Michigan), oxbow ponds, ditches, borrow pits, and even in flooded fields, prairie ponds, and swamps (Bailey 1943; Petranka 1982; Ramsey and Forsyth 1950). Larvae and eggs have been collected in streams in several states as disparate as Indiana (Kraus and Petranka 1989) and Texas (Burt 1938). Ambystoma texanum often breeds in shallower water than other species of the genus and may use ponds that are only an inch or so deep. Minton (2001) reported finding several egg masses of this species in a temporarily flooded lawn in Indianapolis, Indiana. The adults of this species are often explosive breeders, migrating to the breeding sites at night during rainy weather. Breeding was confined to about one to three encounters during or immediately following these late winter or early spring rains (Kraus and Petranka 1989; Petranka 1984). In Indiana, Minton (2001) found freshly killed adults on the roads on January 1 in New Albany and on January 4 at Indianapolis. Many egg masses and breeding adults were seen in Indianapolis on the night of March 4. In Illinois and Ohio, Ambystoma texanum breeds from late February through March (Cagle 1942; Downs 1989; P. W. Smith 1961). The following description of courtship in Ambystoma texanum in southern Illinois is condensed from Garton (1972). When a male finds a female he begins to nudge her, mainly around the pelvis, cloaca, and tail. Nudging then becomes more intense, and he begins undulating his pelvic region and tail in an exaggerated fashion. The female ignores the male during this performance, and she may move slowly away during this interval. The male then moves away from her and deposits one or

2. Species Accounts

more spermatophores, at the same time pressing and undulating his cloaca against the substrate. When males are courting in groups, they often court other males in the same way they court females. When from six to ten spermatophores are deposited, the female nudges the male. Then mutual nudging mixed with deposition of spermatophores occurs, but the female does not actively follow the male as he moves away to deposit another spermatophore. Males deposit their spermatophores on leaves, twigs, and other spermatophores. When a male deposits a spermatophore, his hind feet are against his cloacal walls, his back is arched slightly, and his tail is elevated and undulated. A male may deposit thirty to forty spermatophores before the courting process is over. When the female finds a spermatophore she puts her cloaca above it and then squats and picks up the seminal fluid. A female may collect sperm from eight or more spermatophores. Ambystoma texanum spermatophores are about 5 mm (.2 in.) high and have a somewhat oval base that is about 5 mm (.2 in.) in diameter. The stalk of the spermatophore tapers upward, is slightly flared at its apex, and holds the sperm mass sitting on the four horns of the apex (Labanick and Davis 1978). The females then deposit eggs either singly, in a loose cluster, or in small masses. Minton (2001, 64) reported that in Indiana “spermatophores and eggs are attached to submerged twigs, leaves, stems, fence wire, or similar objects. Egg masses are globular to sausage shaped and contain about 3 to 30 eggs in soft and flimsy jelly. Eggs in the field require 2 to 8 weeks to hatch depending on water temperature. The tempo of larval development is rapid as befits a species breeding primarily in transient pools.” Shortly after emerging from the egg, Small-mouthed Salamander larvae begin feeding on small zooplankton. Older larvae feed both from the water column and on the bottom, eating larger animals as they grow (McWilliams and Bachmann 1989). In Indiana, Whitaker et al. (1982) found that Ambystoma texanum larvae fed on Daphnia, Asselus, ostracods, clam shrimp, midge larvae, and other forms of small invertebrate life. Also in Indiana, Minton (2001) found a large larva that had eaten two smaller A. texanum larvae. He also reported that he found Small-mouthed Salamander larvae at “the point of transformation” in Adams County, Indiana, on May

30; in Vanderburgh County, Indiana, on June 12; and in Delaware County, Indiana, on June 22. Transformed A. texanum generally leave the breeding sites within several weeks and live in various woodland hiding places until they become sexually mature. Parmelee (1993) found that in a floodplain site in southern Illinois, juveniles lived under various kinds of cover for a month or two after metamorphosis and then moved underground when the weather turned hot. Both adults and juveniles can be found under moist logs and various types of litter from March to June. Surface activity is highest in March during the breeding season and then declines progressively. Animals recaptured from the Parmelee southern Illinois site revealed that A. texanum individuals stay in the same activity area for long periods and that individuals frequently share the same cover objects. Although the adults do not appear to be territorial, they infrequently share these shelters with other species. Males are less likely to be found with another male than with a female, but females do not appear to avoid the same sex. Diet Descriptions of the diet of Small-mouthed Salamanders in Michigan are vague (e.g., Harding and Holman 1992). In Indiana, Whitaker et al. (1982) reported that earthworms were the most common food of the adults, with aquatic sowbugs (Asselus) and the salamanders’ own shed skin being eaten often. Centipedes and lepidopteran larvae were commonly eaten as well. Predation and Defense Small-mouthed Salamander larvae are eaten by Ambystoma tigrinum larvae as well as by aquatic insects (Wilbur 1972). Minton (2001) mentioned the defensive behavior of Small-mouthed Salamanders in Indiana. The salamanders elevate and undulate their tail while holding their body motionless and pushing their head against the substrate. Meanwhile glands on the tail exude a sticky white material. Allyn and Shockley (1939) reported that an Indiana Copperhead (Agkistrodon contortrix) seized a Small-mouthed Salamander and released it immediately, showing signs of distress. However, gartersnakes (probably Thamnophis sirtalis) and watersnakes (probably Nerodia sipedon or N. erythrogaster neglecta) eat these salamanders readily.

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The Amphibians and Reptiles of Michigan

Interaction with Humans Relative to Ambystoma texanum in the Great Lakes region, where they are often uncommon or rare, Harding (1997, 71–72) stated that “management would include the preservation of woodlands with known populations, along with maintenance of adjacent shallow, fish-free ponds that hold water into midsummer.” Maintaining and creating wildlife corridors and preserving buffers and critical zones adjacent to breeding ponds is also vital.

tan spots, streaks, and blotches on the head, back, sides, and tail. The belly is brownish, yellowish, or gray and also has spots or streaks. The adult total length ranges from about 178 to 229 mm (7–9 in.). Harding and Holman (1992) reported that one Tiger Salamander reached 330 cm (13 in.) in total length. The larvae of Eastern Tiger Salamanders are large and voracious (see fig. 43).

Behavioral Characteristics For the behavioral characteristics of Small-mouthed Salamanders, see the sections “Reproduction and Growth” and “Predation and Defense” in this account. Population Health As already pointed out, populations of Small-mouthed Salamanders are often rare or uncommon in the northern part of their range in the Great Lakes region. In the few counties in southeastern Michigan where this species occurs, it is extremely rare, and it is considered an endangered species in the state. By law it should not be taken or possessed. General Remarks In most of its range, the Small-mouthed Salamander is a hardy species and more of an “ecological opportunist,” both as a larva and an adult, than many other species of Ambystoma. It will be interesting to see if global warming causes an enrichment or expansion of Ambystoma texanum populations in the state. We may have too much sandy soil in Michigan, at least in the northern part of the state, for very much expansion to occur. Landscape fragmentation is likely another major limiting factor.

Ambystoma tigrinum tigrinum (Green 1825) Eastern Tiger Salamander Identification Eastern Tiger Salamanders are the largest and most robust of the Ambystoma species in Michigan. They have round heads, relatively small eyes, and broad, rounded snouts. Their color is variable, but they all have a dark brown, olive gray, or black background with many yellow, olive, or

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FIGURE 42. Eastern Tiger Salamander (Ambystoma tigrinum tigrinum) from Ingham County, Michigan. Photograph by James H. Harding.

Some adult Tiger Salamanders retain prominent external gills and other larval features, are permanently aquatic, and may become larger than fully metamorphosed individuals of the species. Some gilled adult Ambystoma tigrinum as well as some metamorphosed adults are cannibalistic (Petranka 1998). The following paragraphs include more information about the gilled adult Ambystoma t. tigrinum in Michigan with the hope that readers observing aquatic habitats in the state might discover more of these interesting creatures. All six recognized subspecies of Ambystoma tigrinum (A. t. diaboli, A. t. mavortium, A. t. melanostictum, A. t. nebulosum, A. t. stebbinsi as well as A. t. tigrinum, the species found in Michigan) have these gilled adults. Although Ambystoma tigrinum tigrinum occurs throughout a large portion of the eastern third of the United States, extending from Texas northward to southern Manitoba, Canada (see Conant and Collins 1998, 441, map), gilled adults of this subspecies are known only in Michigan (Hensley 1964; Jones et al. 1993; Petranka 1998). The adaptive advantage for gilled adult Tiger Salamanders is that with gills they can live and reproduce

2. Species Accounts

FIGURE 43. Mature larval Eastern Tiger Salamander (Ambystoma tigrinum tigrinum) from Cook County, Illinois. From C. H. Pope (1944), courtesy of the Chicago Natural History Museum.

in ponds at times when the surrounding areas are uninhabitable or at least stressful for the species. The first Eastern Tiger Salamanders known to come from the Upper Peninsula of Michigan were identified by M. M. Hensley of the Zoology Department at Michigan State University when two specimens were brought to the laboratory for identification by V. Wilderspan, an MSU student. The animals came from a small lake in Alger County in the Upper Peninsula, where they had been collected in 1962. This lake is in the Kingston Plain area, which, at least at that time, consisted mainly of stumps, scrubby vegetation, and poor, acidic soils left over from the logging era. The larger gilled specimen measured 240 mm (9.45 in.) in total length and had both enlarged oviducts and well-developed eggs in both ovaries. The smaller gilled specimen, found alive on September 5, 1962, measured 115 mm (4.53 in.) in total length. Hensley visited the locality again on June 10, 1963, and collected a third specimen that measured 135 mm (about 5.3 in.) in total length. This individual was kept alive, and it metamorphosed into a “normal” individual three weeks after it was collected. This Kingston Plain population, as far as I am aware, is still the only one in the Upper Peninsula of Michigan. According to Hensley (1964, 204), “The presence of this population of tiger salamanders so far removed from the contiguous range of the species suggests interesting zoogeographical probabilities.” Two sets of gilled adult Ambystoma t. tigrinum are known from the Lower Peninsula. A series of eight gilled adult specimens in the collection of the Museum of Zoology at the University of Michigan are from Crawford County in the upper part of the Lower Peninsula (Hensley 1964). Gilled adults were found at

two newly built, fishless experimental ponds that were allowed to colonize “naturally” at the University of Michigan E. S. George Reserve near Pinckney in the southeastern part of the Lower Peninsula (Jones et al. 1993). General Distribution The general distribution of the species Ambystoma tigrinum extends from southern British Columbia, Alberta, and Saskatchewan, Canada, eastward through Minnesota and Michigan and southward (with a gap in the general Appalachian region) to northern Florida; then eastward through Texas to New Mexico, south to central Mexico, and north to eastern Idaho and western Montana. The range of the subspecies Ambystoma tigrinum tigrinum, the form that is found in Michigan, was discussed in the previous section with a reference to a map in Conant and Collins (1998). Michigan Distribution The distribution of Ambystoma tigrinum tigrinum in Michigan is intriguing to say the least. As far as I am aware, this salamander has not been recorded on islands in Michigan waters (e.g., in Bowen and Gillingham 2004). The Eastern Tiger Salamander is widespread in the bottom three tiers of counties in the Lower Peninsula, where records are lacking from only St. Joseph, Lenawee, Monroe, Macomb, and Eaton counties. This species has not been reported from the central part of the Lower Peninsula except for a record in Clare County. In the upper third of the Lower Peninsula records are available from Manistee, Crawford, and Otsego counties. The record from Crawford County includes gilled adult individuals. In the Upper Peninsula the only record of this species is from Alger County, and this population is or was composed of all gilled adults, referred to earlier in this account. It is tempting to suggest that the absence of this species in certain areas of Michigan may be from a

47

The Amphibians and Reptiles of Michigan

combination of intense agricultural activity in the center of the Lower Peninisula and the presence of sandy, acidic soils in areas of both peninsulas. Perhaps the only sporadic presence of isolated gilled adult populations is a reflection of these rather “undesirable” habitats for this species. However, another potential factor could be a lack of observers documenting this species’ presence. These salamanders migrate early in the spring and spend most of their time underground, limiting the possibility for encounters. Any observations should be reported to the Michigan Herp Atlas Project at the MDNR. Geographic Variation So far no populations of Ambystoma tigrinum tigrinum have been discovered that are different enough to warrant a new subspecific name. Habitat and Habits Harding and Holman (1992) pointed out that these salamanders can exist in a variety of habitats in Michigan—including woodlands, fields, marshes, farmlands, and suburban areas—where suitable breeding ponds are available. Tiger Salamanders spend most of their time underground and either use burrows dug by other animals or actively construct their own by digging with their front limbs. Collins and Wilbur (1979) reported that in the E. S. George Reserve in Livingston County in southeastern Michigan, Eastern Tiger Salamanders live in upland fields where they probably utilize small-mammal burrows. Eastern Tiger Salamanders often wander in the spring and early fall during rainy periods, but I once saw a large adult moving around at 3:00 p.m. near the edge of a woods in Ingham County, Michigan, during a dry spell in the fall. Perhaps this individual was looking for a moister place to go underground. During these spring and fall walks, they often become trapped in window wells, basements, and swimming pools. Duellman (1954) observed more than two hundred juveniles and adults that were killed by cars as they moved about on rainy nights in southeastern Michigan in October and November. M. M. Hensley and I found a mass of Ambystoma tigrinum in a most unusual situation. We were watching a Ping-Pong game in a room in the basement of the former Kellogg (cornflake entrepreneur) mansion at the W. K. Kellogg Biological Station in southwestern

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Michigan during an MSU zoology department faculty retreat in October 1973. Someone missed a serve, and the ball rolled slightly downhill into the southeast corner of the adjoining room, a dark place that apparently served no purpose. Massed in this corner, on top of one another in layers, was a huge, somewhat fidgety pile of Eastern Tiger Salamanders. The individuals in the pile were all about the same size and appeared to be recently metamorphosed individuals. Using a crude reckoning process, we estimated that at the very least 250 individuals were in the pile. We looked around with a flashlight for a large crack in the structure that might have let the salamanders enter from the outside, but we could not find one. Given the time of the year, all we could guess was that it was a group of individuals intending to spend the winter there. How they entered the room from the outside we could never determine. Reproduction and Growth Eastern Tiger Salamanders are opportunistic breeders, using fishless woodland ponds, farm ponds, ditches, and marshes as sites. They occupy breeding sites in Michigan with other species but tend to choose deeper water (Harding and Holman 1992). The E. S. George Reserve in the southwest corner of Livingston County in southeastern Michigan is a relatively undisturbed area where the present assemblage of amphibians has probably been stable for about 2,599 years (e.g., Dorr and Eschman 1970). Here, Collins and Wilbur (1979) reported that large populations of Ambystoma tigrinum bred in the temporary Burt and George Ponds on the reserve and that smaller populations bred in the larger ponds. Sadly, in recent years the area has become invaded with exotic invasive plants, reducing the overall habitat quality from what it once was. In five temporary ponds on a 20-ha (49.4 acres) woodlot isolated by cultivation in adjacent Washtenaw County, J. C. Ball (1999) was able to trap only two Eastern Tiger Salamanders (both adults) during his winter/spring studies in 1997. On the other hand, he was able to trap 797 Blue-spotted Salamanders, 111 Eastern Newts, and 54 Spotted Salamanders (all adults) at these ponds during the same breeding season. Relative to this temporality, Minton (2001, 47) reported that in Indiana “breeding ponds for this species [Ambystoma t. tigrinum] may be clear or muddy, rich in hydrophytes

2. Species Accounts

or almost without higher plants, but usually hold water through the summer in normal years.” Harding and Holman (1992) reported that Michigan Eastern Tiger Salamanders breed in March or April. Ruthven et al. (1928) stated that this species is found in ponds in March and April. David Mifsud (pers. comm.), at a Washtenaw County site from 2008 to 2010, observed this species migrating to breeding ponds and mating at the same time as the Small-mouthed Salamanders—often when snow was still present and much of the pond frozen in ice. A more precise breeding date is provided by Sever and Dineen (1978) and Couture and Sever (1979), who found Eastern Tiger Salamanders in their study pond near South Bend, Indiana, late in February, with eggs laid between March 11 and April 11. The eggs were usually laid during periods of rain when the air temperatures were more than 10ºC (50ºF) and the water temperatures more than 8ºC (46.4ºF). Minton (2001) reported that he took Eastern Tiger Salamander males in breeding ponds on February 24 and saw eggs and spermatophores of this species near Logansport, Indiana, on March 27. Again in Indiana, Peckham and Dineen (1954) reported that male Eastern Tiger Salamanders arrived at breeding ponds at about the same time as females and that adults remained there from ten to twenty-nine days. Also in Indiana, Sever and Dineen (1978) reported that males usually stay longer at the breeding site than females and that most females breed every year. The following account of courtship applies to Ambystoma t. tigrinum only. The account is condensed mainly from S. J. Arnold’s account (1976). Usually adults gather in groups of two or three in breeding ponds to court (although Mifsud has found as many as five males courting a single female). When a male finds a female, he moves along the length of her body, at the same time nudging her, swinging his head, and lifting her vent. He then pokes his snout against the side or bottom part of her body and shoves her about. The male then moves away from the female but maintains contact by tapping his tail on her back. The female then moves forward and pushes her snout against his cloaca, which causes him to move forward with his tail raised and deposit a spermatophore. During this interval, the male stretches out, raises his limbs above the substrate, and rapidly undulates his tail.

The female then moves forward until her vent makes contact with the spermatophore, which she moves over and inserts in her cloaca. During this process, she moves and postures in a manner similar to that of the male when he was depositing the spermatophore. If the female continues to be responsive, the male may move forward while feeling for the female’s position with his tail and may deposit more spermatophores. Male Eastern Tiger Salamanders often engage in sexual interference by pushing a female away from another male. A male may also move between a female and rival male, and while mimicking the female’s behavior, the first male may cover the spermatophore of the rival male with his own. Male Ambystoma t. tigrinum deposit an average of twenty-one spermatophores per night with a maximum number of thirty-seven recorded. Compared to other species of Ambystoma, Tiger Salamanders have large spermatophores. The sperm cap sits in the quadrangular apex of the spermatophore neck, which has four raised horns. The neck is directed forward, which may facilitate the capture of the sperm cap by the female. J. D. Anderson (1970) reported that in New Jersey, male Ambystoma t. tigrinum attach their spermatophores to debris, twigs, and willow leaves lying on the bottom of the pond. The spermatophore is 8 to 10 mm (.31–.39 in.) tall and the base tapers narrowly to form a neck that is 2 to 3 mm (.08–.12 in.) in diameter. Eastern Tiger Salamanders deposit their eggs in masses on twigs, aquatic plant stems, and other similar objects in the ponds. The eggs are 2 to 3 mm (.08–.12 in.) in diameter at the pigmented pole where the embryo is to develop and are surrounded by three envelopes. The newly deposited egg masses are roughly globular in shape and average about 60 mm (2.4 in.) in diameter at their greatest width. As the embryos develop, the egg mass swells and becomes rather sloppy looking. In Indiana, eggs of Ambystoma t. tigrinum hatch during late March or early April, and larvae 40 to 60 mm (1.57–2.36 in.) in length were obtained on May 29 in Clark County (Minton 2001). Minton also reported that larvae transform in July in Indiana at total lengths of 85 to 100 mm (3.35–3.94 in.). In an Indiana population studied by Sever and Dineen (1978), embryos hatch in April, and if the ponds begin to dry, the larvae can metamorphose in early to mid-July; at this time they measure 49 to 63 mm (1.93–2.48 in.) in snout-to-vent

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The Amphibians and Reptiles of Michigan

length. A reported population of gilled adult A. t. tigrinum was observed in Tippecanoe County, Indiana (pers. comm. of H. Whiteman to S. A. Minton, reported in Minton 2001). About Eastern Tiger Salamanders in ponds at the E. S. George Reserve in southeastern Michigan, Collins and Wilbur (1979) reported that the larvae were voracious predators and had an important role near the top of the pond’s food web. Relative to Ambystoma t. tigrinim larvae from the same ponds in Michigan, Wilbur (1972) reported that Wood Frog (Rana sylvatica) and (Ambystoma) larvae were major prey items. In Indiana, a population of Eastern Tiger Salamander larvae fed on chironomid larvae, clam shrimp, cladocerans, copepods, ostracods, rotifers, insects, water mites, amphipods, oligochaetes, gastropods, and American Toad (Bufo americanus) tadpoles (Sever and Dineen 1978). Eastern Tiger Salamander larvae may also cannibalize their own species (including their own brother and sister larvae). Lannoo et al. (1989) discovered that the cannibalistic larvae had faster growth rates and shorter larval periods than Ambystoma t. tigrinum larvae that fed on prey of other species, but that size at metamorphosis was not affected by the two types of diet. Diet Oddly, not much is known about the diet of adult Eastern Tiger Salamanders. In fact, much of what has been reported on this subject is based on captive specimens. Harding and Holman (1992) generalized about the diet of adult Ambystoma t. tigrinum, stating that they feed on insects, worms, slugs, and snails. C. H. Pope (1944, 51) stated that “captive specimens are well known to devour almost any animal small enough to be swallowed whole. Earthworms, mollusks, insects, fish, frogs, other salamanders, and even baby mice are accepted.” Based on my experiences in raising Eastern Tiger Salamanders since a boy of ten, I have no doubt that all of these items have been eaten by this subspecies in the wild. In this respect, I would not hesitate to call Ambystoma t. tigrinum “the Bullfrog of the Ambystoma clan.” Once, while trying to introduce a pet Eastern Tiger Salamander to a high-protein item and calcium at the same time, I put a bit of steak covered with bone meal on the floor of his terrarium. He calmly walked over to this item, nudged it with his rostrum, and then gulped it

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down. He also acclimated to eating dried reptile pellets from a small dish. Predation and Defense The eggs of Ambystoma t. tigrinum are eaten by caddis flies (Dalrymple 1970). Morin (1983) reported that Brokenstriped Newts (Notophthalmus viridescens dorsalis) eat the eggs of Eastern Tiger Salamanders. Rose and Armentrout (1976) reported that Tiger Salamander larvae consume eggs of their own species. Little published information describes cases of predation on adults of the Eastern Tiger Salamander. Larvae of this salamander, however, are eaten by insect predators (both larval and adult), Marbled Salamander larvae, and gartersnakes. Birds that eat A. tigrinum larvae include bitterns, grackles, and killdeers. Owls, Eastern Hog-nosed Snakes, Blanding’s Turtles, and badgers have been documented eating the adults in Kansas (Collins 1993). After a torrential rain in Trego County in northwestern Kansas on July 18, 1975, my paleontological field crew and I saw many Blotched Tiger Salamanders (Ambystoma t. melanostictum) crawling at night on a dirt road adjacent to the Saline River. On July 20, we examined owl pellets under the perch of a great horned owl near the vicinity of the salamander crawl. One of these pellets contained the skeleton of an adult Blotched Tiger Salamander (Holman 1976). I have no doubt that great horned owls are also predators of wandering Eastern Tiger Salamanders in Michigan. Interaction with Humans Regarding Ambystoma tigrinum in general, C. H. Pope (1944, 51) stated that “like the spotted salamander, this species has long been standard material for workers in experimental zoology, and thousands are raised annually in scientific laboratories.” Harding (1997, 80), presumably in regard to Ambystoma t. tigrinum in the Great Lakes region, stated that “in some places larval Ambystoma, mostly A. tigrinum, are captured, usually with seine nets, and sold for fish bait.” I have been a denizen of bait shops in many parts of Michigan for about the last forty years and can happily report that I have never seen any Ambystoma larvae for sale, although there are reports of salamander larvae being sold at bait shops along Lake Erie. I do not doubt, however, that local fishermen seine them for personal use from time to time

2. Species Accounts

and that this species is opportunistically used for bait when found. As mentioned earlier in this account, cars can kill hundreds of salamanders during the occasional periods of mass movement of these animals. The draining and polluting of ponds and wetlands as well as the introducing of game fish into formerly fishless habitats are quite harmful to Ambystoma tigrinum. On the other hand, the construction of fishless ponds and pools in Michigan can provide new breeding sites for these salamanders. Behavioral Characteristics For the behavioral charcteristics of Ambystoma tigrinum, see the “Reproduction and Growth” and “Predation and Defense” sections of this account.

twenty-seven genera are currently recognized as well as upward of 240 species. Despite this diversity, all of the species of the Plethodontidae lack lungs (all breathing is done through the skin), which is the most distinctive characteristic of the family. Plethodontids have structures called nasolabial grooves, which are thin channels that extend from the nostril to the outside of the upper lip (see fig. 44). These grooves transport chemicals from the substrate to a sense organ (the vomeronasal organ) that interprets various chemical messages, including those that elicit behavioral responses. In sexually active males of some species, the nasolabial grooves extend downward into two projections on the upper lip called “cirri.” Costal grooves also are present.

Population Health Although the distribution of Ambystoma t. triginum is unusual in Michigan and the abundance of this animal varies from place to place, it is presumably stable in some parts of the state. The Eastern Tiger Salamander is presently identified as a Species of Greatest Conservation Need. General Remarks The mindless slaughter of thousands of Ambystoma tigrinum crossing roads in mass migrations not only in Michigan but over most of the range of the species is disheartening. In Europe, including Great Britain and Germany, tunnels are constructed under the roads in various hot spots where amphibian migrations are known to occur. These tunnels work, as the various migrants prefer to use them to reach their breeding sites rather than cross on the pavement. Recently, efforts have been made in some parts of the United States to seasonally close roads for salamander migration and to integrate barrier fences and culverts to facilitate safer migration to and from breeding sites. In Washtenaw County, a barrier fence has been constructed to prevent Mole Salamanders from crossing a road during their migration.

Family Plethodontidae The Plethodontidae (Lungless Salamanders) comprises the largest family of salamanders in the world and contains an amazing diversity of life forms. About

FIGURE 44. Nasolabial groove in the Eastern Red-backed Salamander (Plethodon cinereus). This is the line running from the upper nostril to the upper lip. From C. H. Pope (1944), courtesy of the Chicago Natural History Museum.

Plethodontid species that spend all their lives on land tend to have round tails. Those that breed in streams often have keeled, triangular tails. Forms that spend most of their lives underground may have reduced limbs, and highly arboreal species tend to have prehensile (grasping) tails and feet that have either webbed or square toes. Plethodontid salamanders are far more abundant in the Appalachian region of North America than any other area of similar size in the world. Plethodontids are widely distributed in both eastern and western North America, Mexico, and Central America. Two genera presently occur in South America. In continental Europe one genus, Hydromantes, with two species occurs. The same two species also occur on the island of Sardinia. Only two plethodontid genera, each with a single species, presently occur in Michigan.

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The Amphibians and Reptiles of Michigan

Hemidactylium scutatum (Temminck and Schlegel in Von Siebold 1838) Four-toed Salamander Identification This elfin salamander is distinguished by having only four tiny toes on each of its hind feet (have your hand lens ready to count them). Four-toed Salamanders have a long tail that is constricted at the point where it joins the body. The belly is white with well-defined black spots and blotches. The back is a rusty brown color, and the sides of the body are grayish. The back is usually speckled with black and bluetinted flecks. This species has thirteen to fourteen costal grooves, and the total length of an adult is from 50 to 102 mm (about 1.97 to 4 in.) (Harding 1997). General Distribution The distribution of Hemidactylium scutatum is fairly continuous from extreme southern Maine in the United States, extreme southern Quebec and Ontario in Canada, and northern Wisconsin southward to the Fall Line in North Carolina, South Carolina, Georgia, Alabama, and Tennessee, with presumably disjunct populations occurring in Nova Scotia (Canada), Mississippi, Arkansas, Louisiana, Georgia, and northern Florida (Frost 1985). Michigan Distribution Four-toed Salamanders are found in every county in Upper Michigan. As far as I can determine, it has not yet been discovered on any of the Michigan islands. Hemidactylium scutatum is well represented by county records in the northern third of the Lower Peninsula, and the reason for a lack of records from several counties there may be the secretive nature of the species. Records of Four-toed Salamanders are rare in the central and southern parts of the Lower Peninsula. If you think you have found this species, contact the Michigan Herp Atlas Project at the MDNR. Geographic Variation The genus Hemidactylium is monotypic (only one species occurs in the genus), and no subspecies are currently recognized (Crother 2008). It is possible that detailed studies of geographic variation in H. scutatum will result in the naming of subspecies.

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Habitat and Habits Adults and juvenile Four-toed Salamanders inhabit woodlands adjacent to bogs, swamps, marshes, and other shallow bodies of water that lack fishes. In Michigan this species is often found during the breeding season under mats of sphagnum near the edge of marshes and bogs (M. M. Hensley, pers. comm., May 1968). Petranka (1998) reports that in northern localities, adult H. scutatum may be found beneath various objects on the forest floor, but that those in the southern portion of their range are more likely to be beneath the surface.

FIG. 45. Four-toed Salamander (Hemidactylium scutatum) from Michigan. Photograph by James H. Harding.

Reproduction and Growth In Michigan, mating in Hemidactylium scutatum occurs in the fall. In the spring the females migrate back to the breeding site to deposit their eggs. Males do not accompany them. Michigan females can be found in late October and November with sperm in their cloacae (Blanchard 1933a). A large number of juvenile specimens collected in Michigan showed that the sexes were virtually equal in number, with the females slightly outnumbering the males (Blanchard 1935). Males that were collected in Michigan deposited over 120 spermatophores each between November 2 and December 2 (Branin 1935). Branin (1935) provided an account of courtship of captive Four-toed Salamanders, which is condensed as follows. Males start the courtship process by nosing both sexes. When a male finds a female, he will generally move in a circle with his tail held at a right angle to his body. When aroused, the female straddles the tail of the

2. Species Accounts

male and puts her chin on the top of his tail base. The male then goes forward, undulating his tail from side to side. The female follows, still straddling the male and keeping her chin in contact with the base of his tail. The “tail-straddle walk” may continue for as long as twenty minutes. Although Branin saw the females pausing over spermatophores, he did not detect any pickups. Blanchard (1933a) observed that Michigan male Four-toed Salamanders deposit only one or two spermatophores at a time. A spermatophore, deposited by a captive male on a leaf in Blanchard’s laboratory on October 1, had a disk-shaped base about 2 mm wide that tapered upward into a stalk about 1 mm in diameter and ended in a pale yellow top containing sperm. Oviposition in southern Michigan occurs from April 14 to May 12 (Blanchard 1934a). Mats and clumps of moss are the most common places where oviposition occurs. Female Four-toed Salamanders brood their eggs in solitary nests or in communal nests. Blanchard (1922) first reported these two kinds of nests. He later stated that at the beginning of the egg-laying season in Michigan, from one to several females can be found in a single nest (1934b). Once, on April 14, 1931, he had observed from one to fourteen females per single nest. Seven nests had only one individual each and seven nests were jointly occupied. He stated that later in the season, usually only one female is found per nest, based on studies of nests from May 6 to May 25. Breitenbach (1982) studied 109 Hemidactylium scutatum nests from 1979 to 1981 from various localities in Michigan. The 1980 and 1981 data came from five bogs at the E. S. George Reserve in Livingston County, Michigan. Breitenbach found that communal nesting occurred in only 13 of 109 (12 percent) of the nests he observed. One communal nest was found at the Lake Ridge Bog at the Pinckney Recreation Area. Four single and eight communal nests were found at the George Reserve in 1980 and 1981. Unattended nests were found at all stages of egg development, but unattended nests were more common in the early stages of embryonic development. All females abandoned their nests just before the eggs hatched. At the Finger Pond South locality at the George Reserve, of 36 marked nests, 32 were in clumps of Sphagnum, two were in rotten wood, one was in a grass “hummock,” and one was in leaf litter.

The average incubation period of Hemidactylium scutatum in Michigan is thirty-eight days, and hatchlings or embryos about ready to hatch have been found in May (Blanchard 1923). Very little has been written about the biology of Four-toed Salamander larvae. However, Blanchard (1923) gave an account of larval H. scutatum in Michigan. A short time after hatching, the larvae wriggle through the mats of moss or other surface cover and enter a pond. Here they have a very short larval period of about six weeks. The larvae eat zooplankton and other invertebrates. Transformation to a juvenile state occurs in July, when the larvae reach about 18 to 24 mm (.71–.94 in.) in total length. Juvenile H. scutatum leave the breeding ponds after only a few weeks and live in woodlands until they are sexually mature. F. N. Blanchard and F. C. Blanchard (1931) reported that in Michigan both males and females reach maturity about twenty-eight months after they hatch. Males are about 49 to 57 mm (1.93–2.24 in.) in total length and females about 62 to 68 mm (2.4–2.7 in.) in total length at this time. By late fall both juvenile and adult Four-toed Salamanders assemble and sometimes congregate with other salamanders and frogs. On November 5, 1922, Blanchard (1933b) observed eighteen Hemidactylum scutatum in or next to a decomposing log in Ingham County, Michigan. These individuals were in cavities within the decaying wood or under adjacent leaves. In association with the Fourtoed Salamanders, he found a Red-backed Salamander (Plethodon cinereus), five Blue-spotted Salamanders (Ambystoma laterale), a Spotted Salamander (Ambystoma maculatum), an Eastern Newt (Notophthalmus viridescens), and an Eastern Gartersnake (Thamnophis sirtalis sirtalis). On November 9, 1924, Blanchard (1933b) discovered a few less than two hundred Four-toed Salamanders under leaf litter in Livingston County, Michigan, in an area of “very few square feet.” A veritable mass of other amphibians were associated with the Hemidactylium scutatum. These associates included 114 Northern Spring Peepers, 88 Western Chorus Frogs, 48 Wood Frogs, and small numbers of Blue-spotted and Eastern Red-backed Salamanders and Newts. The latest in the year that Blanchard ever found a Four-toed Salamander above ground in Michigan was on December 1, 1921, when he found two individuals under some wood chips.

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The Amphibians and Reptiles of Michigan

Diet Regarding Michigan Four-toed Salamanders, Ruthven et al. (1928) reported that the food of this species probably consists of small insects; they also mentioned that fruit flies were eaten by captive specimens. Harding and Holman (1992) reported that this salamander eats small invertebrates, mainly spiders and insects. C. H. Pope (1944, 57) reported that one stomach of this salamander contained spiders, springtails, drosophilid flies, and homopterous bugs and that another contained remains of staphylinid beetles and moth larvae. Predation and Defense Petranka (1998) reported that predation is not well documented in Four-toed Salamanders but suggested that vertebrates such as small woodland snakes, shrews, and birds probably prey on this species. Resetar (1988) presented some evidence that the Masked Shrew (Sorex cinereus) is an important predator of Four-toed Salamanders in Indiana. As a response to a predator attack, Hemidactylium scutatum may lift and undulate its tail while releasing noxious solutions. As in some lizards, Four-toed Salamanders can voluntarily shed their tails even before being seized by a would-be predator. The breaking point occurs at the constricted area at the tail base. The broken-off tail wiggles vigorously and may catch the attention of the predator, allowing the salamander to safely crawl away (Harding and Holman 1992). I am not aware of any studies on the process of regeneration of either bitten-off or voluntarily shed tails. Interaction with Humans I am not aware that Hemidactylium scutatum has been used as a commercial laboratory animal. The spotty distribution of Four-toed Salamanders in Michigan is likely because of the particular woodland bog habitat that it requires for successful breeding. The conservation of such wetland habitats is essential for the population health of this species. Often these breeding sites are not regulated by the state and require regulation and protection at the local level. Behavioral Characteristics For the behavioral characteristics of Four-toed Salamanders, see the sections “Reproduction and Growth” and “Predation and Defense” in this account.

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Population Health At present this salamander is not considered to be threatened or endangered in Michigan, but it is identified as a Species of Greatest Conservation Need. However, I have not observed this species for several years, although I have looked for them in the same boggy Michigan woodland habitats where I found them during the 1970s and 1980s. Gauging their population health is challenging because of their cryptic nature and habitat use. General Remarks Much is yet to be learned about this unique little salamander, showing the need for baseline as well as theoretical ecological studies in Michigan.

Plethodon cinereus (Green 1818) Eastern Red-backed Salamander Identification The Eastern Red-backed Salamander is a small, elongate plethodontid salamander with small legs and feet, five toes on the hind legs, and two distinct color phases. The red-backed, or striped, phase has a background color that is either black or gray with a wide red-orange or orange stripe that runs down the back. The “lead-backed,” or unstriped, phase lacks the red-orange or orange stripe and is dark gray or black above and often has tiny scattered light-colored or bronze spots. Sometimes specimens are found in Michigan that are intermediate between the two phases. In both the red-backed and lead-backed phases, the belly has a mottled white and gray salt-and-pepper pattern. The adult total length in these salamanders ranges from 57 to 127 mm (2.2–5.0 in.) (Harding and Holman 1992). General Distribution The Red-backed Salamander occurs in a range that stretches from the Canadian Maritime Provinces to southern Quebec and northeastern Minnesota, south to northern and eastern North Carolina, and west to Indiana, Michigan, and northern Wisconsin. Michigan Distribution Plethodon cinereus has been recorded in every county in the Upper Peninsula of Michigan. It is found on Isle Royale

2. Species Accounts

and Drummond and Bois Blanc Islands and in the Lake Michigan Archipelago on Beaver, Garden, High, North and South Fox, North and South Manitou, and Squaw Islands. It is also known from North Island in Saginaw Bay. In the Lower Peninsula it has been recorded in every county. Geographic Variation In North America there is much geographic variation in Plethodon cinereus (see Petranka 1998), especially in the variability of color schemes within and between the previously mentioned phases. In the Upper Peninsula of Michigan, only the red-backed phase is found in most populations (Test 1952). The lead-backed phase occurs in small proportions in populations in the extreme southern part of the Upper Peninsula and in the northern part of the Lower Peninsula. The farther south the population is in the Lower Peninsula, the higher the proportion of lead-backed individuals there will be. Near Ann Arbor, in Washtenaw County in southeastern Michigan, Test and Bingham (1948) found that 65.4 percent of 451 individuals examined from one study area were the red-backed phase and 63.3 percent of 128 individuals from another study were also the red-backed phase. The other individuals in these study areas were the lead-backed phase. At one time, isolated populations in Arkansas, Missouri, Oklahoma, Louisiana, Georgia, Alabama, Tennessee, and North Carolina originally assigned to Plethodon cinereus are now called the Southern Red-backed

Salamander (Plethodon serratus Grobman 1944). Protein variation studies figured importantly in the separation of these two species (e.g., Highton and Webster 1976). Habitat and Habits In Michigan, Plethodon cinereus is found in woodlands, especially those with rotting logs and thick leaf litter. Moist forests are especially necessary for them because they lack lungs and must take in oxygen through their moist skin. This salamander can survive in moist woodlands where there are no ponds nearby because they do not have a larval stage. Petranka (1998) points out that populations of these salamanders are usually absent or occur at low densities in highly acidic, wet, or shallow, rocky soils. Regarding the shelters of both juvenile and adult Plethodon cinereus in Michigan, Heatwole (1962) reported that during wet weather this species is active in the leaf litter of deciduous trees. But during dry weather they tend to retreat downward into the humus and mineral soil layer or remain above ground but inside logs and other moist retreats. He also reported that Redbacked Salamanders are rarely found in lichen mats or conifer litter shelters, where hot summer temperatures may exceed the limits of tolerance of these animals. In mark-and-recapture studies of Red-backed Salamanders in Michigan conducted by Heatwole (1962), data showed that during the peak of summer activity the forest floor carried a density of 0.89 individuals per square meter.

Fig. 46. Eastern Red-backed Salamander (Plethodon cinereus) from Michigan. This is a red-backed phase individual. Photograph by James H. Harding.

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The Amphibians and Reptiles of Michigan

Reproduction and Growth The whole life cycle of Plethodon cinereus occurs on land. Courtship and mating occur on land, and the eggs are deposited on land and hatch into small replicas of the adults, except that three gills are sometimes retained for a short time after hatching. In southern Michigan, most mating occurs in the fall, but it can occur in spring as well. Plethodon cinereus studied by Blanchard (1928b) at localities near Ann Arbor, Michigan, had sperm in their cloacae on October 31, November 5 and 6, December 9, and April 19, 21, 25, and 26. About two-thirds of the thirty-four specimens taken on October 31 had already mated. Male Plethodon cinereus breed annually in all areas where they occur, but females breed either annually or every other year, depending on their geographic area and age. Studies in Michigan (Test and Bingham 1948), New York (Bishop 1941), and Wisconsin (Vogt 1981) suggest that most female P. cinereus deposit their eggs every other year rather than annually. A suggested reason is that the growing season in these areas is so short that females cannot obtain enough energy to generate yolk for their eggs annually. However, Werner (1971) points out that in some Michigan populations mature females of all sizes breed annually. Test (1955) reported that in southeastern Michigan the males and females are about equal in number except when the population is sampled during the nesting season, which is when a significant number of females are underground (see fig. 47).

FIG. 47. Adult Eastern Red-backed Salamander tending its eggs. From C. H. Pope (1944), courtesy of the Chicago Natural History Museum.

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The pattern of courtship in Red-backed Salamanders (as in the Four-toed Salamanders) employs the tail-straddle walk, a part of the courtship ritual that is characteristic of the Plethodontidae. The males have recurved teeth on the premaxillary bones that scratch the females’ skin during courtship. This activity is thought to introduce mental gland secretions into the circulatory system of the female. The following account of courtship activities in Plethodon cinereus in Virginia in midOctober is condensed from Gergits and Jaeger (1990). Pheromones are chemical messages secreted from one organism that usually elicit a a specific response in another. They are thought to play an important part in the courtship ritual of Red-backed Salamanders, as males are believed to follow female pheromone trails. When a male finds a female, he positions himself in front of her, sometimes tapping her with his nose. He then bends his tail upward and undulates it laterally. If the female leaves, the male positions himself in front of her again and performs the tail undulation once more. The male then pushes his mental gland back and forth over her back as he moves forward over her body. The next act is the tail-straddle walk, described in the Four-toed Salamander account. This walk continues until the male deposits a spermatophore. After the female picks up the spermatophore, the two salamanders separate. Harding (1997) described the nest and brooding behavior of the female Plethodon cinereus in the Great Lakes region. In early summer from three to seventeen eggs are laid in a grapelike cluster. The nest may be in an underground cavity or in a cavity within a decaying log or stump. This cluster of eggs is usually suspended from the roof of the nest by a gelatinous stalk. The female remains with her eggs, and it has been suggested that she uses skin secretions to keep them moist as well as to ward off mold infections. The female defends her eggs against both invertebrate and small vertebrate predators. Davidson and Heatwole (1960) reported that the incubation period of eggs in Michigan is about six weeks and hatching can occur in August or September. Once, a female in northern Michigan was found ovipositing on August 2 when other clutches were about ready to hatch. Blanchard (1928b) reported that the number of eggs per cluster of ninety-one Michigan female Red-backed Salamanders ranged from five to thirteen, with an average of nine per cluster.

2. Species Accounts

Test and Heatwole (1962) described nesting situations of Plethodon cinereus in northern and southern Michigan. In northern Michigan, nests are often discovered in rotting conifer logs that contain a network of cracks. They can also be found in mammal burrows and in cavities at the interface of the leaf litter and the mineral soil below it. In southern Michigan, they reported that nests are rarely found because they usually occur in the underground burrows of invertebrates and vertebrates. The embryos of Plethodon cinereus possess three gills on either side of the head. These gills are lost just before or shortly after hatching (Piersol 1910). Juvenile Redbacked Salamanders in Michigan become sexually mature about two years after they hatch (Blanchard 1928b; Werner 1971). About growth, Nagel (1977) reported that juveniles in an eastern Tennessee population grew an average of 15 mm (.59 in.) in snout-to-vent length during their first year of life but then only an average of 8 mm (.31 in.) during their second year. Diet Red-backed Salamanders tend to eat about any palatable object they can capture and swallow. In the laboratory the adults are opportunistic cannibals that eat both the eggs and juveniles of other P. cinereus. But Heatwole and Test (1961) found that only two cases of cannibalism had occurred in 317 specimens that they examined in northern Michigan. Blanchard (1928b) found that the diet of Red-backed Salamanders in southern Michigan includes ants, beetles, bugs, mites, spiders, snails, millipedes, mites, springtails, pseudoscorpions, and miscellaneous other invertebrates as well as their own shed skins. Predation and Defense Red-backed Salamanders are also the prey of some invertebrate predators; there is evidence that spiders prey upon Plethodon cinereus in Connecticut (Lotter 1978). Vertebrate predators include woodland snakes, such as the Ring-necked Snake (Diadophis punctatus), Eastern Gartersnakes, and birds that forage in leaf litter. Studies on Diadophis punctatus (Lancaster and Wise 1996) show that this snake can distinguish excreted substances from the tail from those from other parts of this salamander’s body. Red-backed Salamanders often coil when they are

uncovered and are also able to voluntarily shed their tails when molested (Cockran 1911; Piersol 1910). Piersol (1910) found that about 10 percent of his sample of P. cinereus had broken or regenerated tails. C. H. Pope (1944) stated that P. cinereus was an agile jumper and that it used its tail rather than its limbs to do so. He also stated that it was a good climber in spite of its short legs. Some Michigan specimens of P. cinereus that I have uncovered from beneath shelters such as boards or flat pieces of trash have wriggled very rapidly to another flat shelter, sometimes eluding capture in the process. Others that I have uncovered under deepset logs have tended to be more inert and easily captured. Interaction with Humans As far as I can determine, Plethodon cinereus has never been sold commercially; however, this species is seasonally offered on various Internet classifieds that specialize in the sale of amphibians and reptiles. For modern populations, any disturbance of moist woodlands would be detrimental to this species, and clearcutting of moist forest situations would be devastating for them. Behavioral Characteristics Territoriality is highly developed in Plethodon cinereus. Both males and females defend moist microhabitats within their territory (Mathis 1989). The reason for the strong territorial responses in this species is somewhat inadequately known, although the defense of mates and feeding areas is probably most important (e.g., Jaeger et al. 1993). Observations in natural habitats indicate that large P. cinereus were effective in defending desirable cover objects from smaller animals. Moreover, in natural habitats, when residents are removed from logs, the subsequent invaders are smaller than the residents that were removed. Additional studies indicate that larger males occupy the highest quality territories and that these territories are more likely to attract females than those of smaller males. It has also been shown that once a female enters into the territory of a large male, he is more likely to defend his territory from smaller males (Jaeger et al. 1995). “Floaters,” usually smaller salamanders that do not hold territories, can make up a large portion of P. cinereus populations. In Virginia, about 49 percent of a population of Red-backed Salamanders consisted of floaters (Mathis 1991).

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The Amphibians and Reptiles of Michigan

Population Health Plethodon cinereus is widely distributed today in Michigan. Within this broad range though, several authors (e.g., see the list of references in Petranka 1998, 346) have found that Red-backed Salamanders are not tolerant of acidic soils. Experimental evidence indicates that acidic soils may disrupt their sodium balance to the extent that such soils could be lethal to Plethodon cinereus (and to other terrestrial salamanders as well). General Remarks Petranka (1998) made the point that Plethodon cinereus is an excellent model for the examination of the ecological and evolutionary significance of aggression and territoriality in amphibians. The MDNR considers the abundance of Redbacked Salamanders in the woodland ecosystem to be an indicator of a healthy forest environment. The department also points out that if the habitat of this species is modified or destroyed, this animal will soon disappear (MDNR, n.d., Red-backed Salamander). An interesting note provided by David Mifsud (pers. comm.) is that this species is found even in inner-city Detroit parklands where mature high-quality woods still exist.

Family Proteidae The Proteidae is a small family of permanently aquatic salamanders with bushy external gills, two gill slits, a reduced number of toes, and no maxillary bones in the skull. Two genera are presently recognized. Necturus comprises five species, all of which occur in eastern North America. Proteus is a cave form that has only one species, P. anguinus, which occurs only in southern Europe.

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and a depressed (flattened from top to bottom) head. Necturus has only four toes on the hind feet. Its back, sides, and tail are usually brown or grayish brown with scattered dark spots or blotches. The belly may be gray or yellow and is sometimes spotted. The eyes are tiny and lack lids.

FIG. 48. Head and forelimbs of the Common Mudpuppy (Necturus maculosus maculosus) from Michigan. Photograph by James H. Harding.

General Distribution The range of the Common Mudpuppy is from western New England and the St. Lawrence River west to southeastern Manitoba and south to eastern Kansas, northern Mississippi, and western North Carolina (Minton 2001).

Necturus maculosus maculosus (Rafinesque 1818) Common Mudpuppy

Michigan Distribution The Common Mudpuppy has been recorded in every county in the Upper Peninsula and from Isle Royale and Drummond Island. It also occurs in nearshore situations in the Great Lakes that surround Michigan. It occurs in all the tiers of counties in the Lower Peninsula but has not been recorded in some clusters of individual counties here and there.

Identification The Common Mudpuppy is the largest salamander in Michigan, at least by mass. It can reach a total adult length of about 400 mm (15.75 in.). A totally aquatic species, it in many ways resembles a giant larva in that it has three pairs of prominent external bushy gills (and lungs as well), a compressed (flattened from side to side) tail,

Geographic Variation The subspecies Necturus maculosus maculosus occurs throughout Michigan. Mudpuppies along the southwestern border of the Upper Peninsula of Michigan and adjacent northeastern Wisconsin have black or dark gray backs with small black spots, and on some animals, large dark blotches may be found on the

2. Species Accounts

back, sides, and belly. The line through the eye is either difficult to define or absent in large individuals. Hecht (1958) characterized these populations as a poorly defined subspecies (N. m. stictus) but Petranka (1998) and Crother (2008) consider these populations as part of N. m. maculosus. A second valid subspecies of Necturus maculosus, N. m. louisianensus Viosca, the Red River Mudpuppy, is currently recognized (Crother 2008). This animal occurs in eastern Kansas and Oklahoma, southern Missouri, all of Arkansas except the extreme southwestern tip, and northern Louisiana (see Petranka 1998, 427, map). Habitat and Habits Within its range in eastern North America, Necturus m. maculosus lives in a variety of permanent aquatic

Fig. 49. Common Mudpuppy in dorsal view. From C. H. Pope (1944), courtesy of the Chicago Natural History Museum.

situations. Bishop (1926) reported that in the northern part of their range, these animals occur in bays with thick aquatic vegetation and muddy canals as well as in large streams with fast-flowing water and clear cool lakes. Regarding the Great Lakes region, Harding (1997, 43) stated that “mudpuppies inhabit permanent waters, including rivers, reservoirs, inland lakes, and Great Lakes bays and shallows. In clear water they tend to be nocturnal, remaining hidden beneath rocks and other objects during the day. They can be active both night and day in shallow inlets and coves with thick aquatic vegetation. Mudpuppies are primarily bottom-walkers, but can swim with a fishlike motion, their legs folded against the body.” Stationed in various ice-fishing shanties on small frozen lakes and ponds in the southern part of the Lower Peninsula in Michigan, I have seen numerous Mudpuppies caught through the ice by fishermen during February and especially in early March when the ice is starting to degenerate. Reproduction and Growth In Michigan, male and female Mudpuppies gather in shallow water in October and November for mating, but the eggs are not laid until the following spring (Harding and Holman 1992). Oddly, comprehensive accounts of the courtship of this species are not available. Bishop (1926) observed an occasion when a swimming male Mudpuppy crawled between the legs and over the tail of a nonmoving female. Spermatophore deposition did not occur in this situation. Bishop (1932) reported that the spermatophore of Necturus maculosus is composed of a gelatinous base that supports a white, milky mass of sperm, with the whole surrounded by a thin jelly-like layer. The spermatophore is 6 to 8 mm (.24–.31 in.) in diameter and 10 to 12 mm (.39–.47 in.) in height. Bishop (1941) reported that males leave the nest site before the females begin to lay their eggs. Females in southern Michigan deposit their eggs as early as late April (Fitch 1959). In Michigan, female N. maculosus excavate nest cavities under submerged rocks or other flat objects, and pea-sized eggs are suspended from the top of the cavity, each egg hanging from a thin, jellylike stalk (Harding and Holman 1992). Fitch (1959) examined eleven nests of N. m. maculosus in Michigan and found a range of 28 to 101 and a mean of 60 eggs per

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The Amphibians and Reptiles of Michigan

nest. Lagler and Goellner (1941) examined the number of ova in twenty-five Michigan female Mudpuppies and found that the count varied from 75 to 193 with an average of 122. The female tends the nest until the larvae hatch, one or two months later. The larvae range from 20 to 35 mm (.79–1.38 in.) in total length at the time of hatching (Harding and Holman 1992). During the brooding process, females guard the eggs from such predators as fish and crawfish (Bishop 1941). Bishop (1926) studied Necturus m. maculosus hatchlings and found that by the time they are thirteen months old they have reached an average total length of 56 mm (2.2 in.). One-year-old animals grow an average of 26 to 39 mm (1.02–1.54 in.) in total length per year until they are five years old, when they reach a total length of about 187 mm (7.36 in.). Sexual maturity occurs when individuals exceed 200 mm (7.87 in.) in total length. Diet Lagler and Goellner (1941) studied predation in 105 Necturus m. maculosus from Evans Lake in southern Michigan and found that snails, earthworms, Odonata species, mayflies, several species of fishes, a frog, and even an Eastern Musk Turtle (Sternotherus odoratus) (it must have been a very young one) are in the diet of this species. Relative to the Great Lakes region, Harding (1997) reported that Mudpuppies feed mostly at night and eat crawfish and other crustaceans, insect larvae, mollusks, fish eggs and small fish, other amphibians (including smaller Mudpuppies), and carrion, which they locate with their well-developed sense of smell. Ruthven et al. (1928, 14) stated that “at night, Necturus, which is extremely voracious, swims about in search of food, which consists largely of crayfishes, small fishes, fish eggs, insects and worms. Specimens in captivity will snap at any moving object and if hungry enough, will eat small pieces of meat moved about in the water.” Predation and Defense Predators of Mudpuppies in the Great Lakes region include fishes, watersnakes, and herons (Harding 1997). Necturus has sense organs in the skin that are able to detect motion and pressure changes in the water just as with the lateral line system of fishes. These sensors probably help the animals avoid predators as well as find prey.

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Interaction with Humans Until relatively recently, Mudpuppies have been collected by the millions for biological supply houses that fixed them with formalin (now known to be a dangerous substance when breathed or touched barehanded) and injected them so that their arteries turned red and their veins blue. These were shipped mainly to college comparative anatomy classes so struggling premedical students could dissect a typical amphibian. The same was done to frogs destined for high school biology classes to show students what a typical vertebrate looks like (see Holman 2003). A Mudpuppy is a typical amphibian only by a long stretch of the imagination, and to say that a frog is a typical vertebrate is ludicrous. The reason Mudpuppies were used in the labs was that they were abundant, and college biology departments could afford to buy them. Bishop (1926) reported a catch of more than two thousand Necturus in one haul of a commercial seine in Michigan, and also recalls that about five hundred Mudpuppies were caught in Evanston, Illinois, in one day. Harding (1997) pointed out that Mudpuppies are often persecuted in the Great Lakes region because of their odd appearance, slimy skins, and their undeserved reputation as a predator of game fish. Ruthven et al. (1928) reported that fishermen of the Great Lakes were so sure this species was poisonous that they would cut the animal from a hook rather than handle it. Pearse (1921) reported that he found the meat of the Mudpuppy to be of fine quality and very white. In southern Michigan I have seen ice anglers throw Mudpuppies out on the ice to die. This abuse, I am sure, is partly a result of many fishermen not knowing what the creature really is. One Michigan fisherman told me that he was catching “bullheads with legs again.” Behavioral Characteristics Observations in the field indicate that Necturus maculosus is capable of homing. Thirty-three Mudpuppies were captured and carried 128 m (418.8 ft.) downstream. When released, all of them began to swim upstream and four of them were recaptured near the place they were originally caught. Moreover, Mudpuppies that were released at the site where they were originally caught immediately sought shelter there (Shoop and Gunning 1967). Seasonal migration of N. m. maculosus in a lake in

2. Species Accounts

southwestern Michigan has been reported by Gibbons and Nelson (1968). The animals migrate to shoreline areas in the spring and then move back to deeper water in the summer. Population Health Necturus m. maculosus is listed as a Species of Greatest Conservation Need in Michigan. Mudpuppies are in decline in many Michigan lakes and rivers and are sensitive to chemical pollutants (MDNR, n.d., Mudpuppy). I have observed amphibians in or near a lake in northwestern Michigan on an almost weekly basis in the spring, summer, and early fall since 1980. In the early 1980s Common Mudpuppies were abundant in the lake. In the mid-1980s the number of dead individuals that washed up on shore was alarming. The external gills of all the bodies were highly infested with a fungal growth, but I am not sure whether this occurred before or after death. I have not seen a Mudpuppy dead or alive in the lake since 1987. Some factors that might be associated directly or indirectly with the extirpation of Mudpuppies in a lake or other water bodies could include the following: 1. Regular treatment of the water with chemicals to kill the snails that are responsible for swimmer’s itch (Mudpuppies feed on snails and small clams). 2. Occasional treatment of the water for “weed control.” 3. Zebra mussel infestation, resulting in an altered lake community and food webs. 4. Treatment of the lake or water body with sea lamprey larvicide. 5. The washing into the lake of chemical fertilizers and weed-control products that are used to produce a single-species grass crop for the yards of lakeside homes and cottages. 6. Replacement of the natural vegetation of the lake or water body by Eurasian milfoil and false elodea. 7. Treatment of the lake or water body with rotenone to control fish (a chemical that has been known to kill Mudpuppies and some turtle species).

8. Oil and gas surface deposits from motorized watercraft on multiuse lakes (hydrocarbons can harm sensitive gill-breathing animals). General Remarks Necturus maculosus maculosus is much the largest species of salamander in Michigan and is one of the most interesting species of animal in the state as well as in North America. The Mudpuppy used to be abundant statewide but now is in decline and has even been extirpated from many aquatic habitats. Many of Michigan’s threatened or endangered species are animals on the periphery of their range or those that have not been abundant in the state for thousands of years. But when formerly abundant or common species abruptly begin a precipitous decline, it is really frightening for healthy biological communities in Michigan. This disturbing situation seems to be the case with the Mudpuppy. It is listed as a Species of Greatest Conservation Need in Michigan.

Family Salamandridae The salamandrids have a rough, somewhat toadlike skin that contrasts with the smooth, slimy skins of other salamanders. The fact that costal grooves are absent or indistinct also adds to the different aspect of the body of the Salamandridae. Other characters of the family include the lack of labial grooves and the presence of two rows of palatal teeth that extend backward between the orbital (eye socket) area. As far as is known, all salamandrid species produce toxins, and some are very potent. Many species have bright warning colors. The Salamandridae is a relatively large family that has about fourteen living genera and approximately fifty-three species that occur mainly in Asia, northern Africa, and Europe. Only two genera, each with three species, occur in North America. Notophthalmus occurs in the eastern United States and eastern Mexico, and Taricha occurs widely in western North America.

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The Amphibians and Reptiles of Michigan

Notophthalmus viridescens (Rafinesque 1820) Eastern Newt (composite range of two intergrading subspecies) Identification Newts have a life cycle made up of three phases: an aquatic larval stage, an intermediate terrestrial stage (called an “eft”), and an aquatic adult stage (called a “newt”). Two subspecies of Notophthalmus viridescens occur in Michigan. Distinguishing characters of these are given in the “Geographic Variation” section of this account. Eastern Newt subspecies in Michigan can be easily identified because they have dry, granular, somewhat toad-like skin that contrasts with the thinner, slimy skin of other Michigan salamanders. A lack of distinct costal grooves and the presence of two longitudinal ridges that occur on the top of the head distinguishes both the efts and newts of this species.

FIG. 50. Eastern Newt (Notophthalmus viridescens) from Michigan. Photograph by James H. Harding.

General Distribution Notophthalmus viridescens occurs from the Maritime Provinces of Canada south through Florida, west to southern Texas, and north through Minnesota to Ontario, Canada. The distribution of the species in Minnesota is fragmentary. Michigan Distribution Notophthalmus viridescens has been recorded in every county in the Upper Peninsula. It occurs on Isle Royale,

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Drummond and Bois Blanc Islands, and Charity Island in Saginaw Bay. In the Lake Michigan Archipelago, it occurs on Beaver, Garden, High, and South Manitou Islands. In the Lower Peninsula, records are widespread, and it probably occurs in most if not all of the counties in the state. Geographic Variation Notophthalmus viridescens occurs in the form of two subspecies in Michigan. The Red-spotted Newt, N. v. viridescens (Rafinesque 1820), occurs in the southeastern part of the Lower Peninsula. The Central Newt, N. v. louisianensis Wolterstorff 1914, occurs in the rest of the state. To outline the general division between these subspecies, draw a straight line between the southwest corner of Branch County in the first tier of counties in the Lower Peninsula to the southeast corner of Bay County in the Saginaw Bay area. However, it may be difficult to precisely identify the subspecies close to either side of the line because Conant and Collins (1998) state that Central Newts intergrade (crossbreed) with Red-spotted Newts over a broad area in Michigan. Probably the best way to distinguish these two subspecies of Eastern Newts is by the spots on their back. The Red-spotted Newt has up to about twenty red spots bordered in black. The Central Newt usually lacks the red spots, and if they do occur, they are smaller and have faded or incomplete black borders. More information is needed about the zone of intergradation between the two subspecies of Eastern Newts in Michigan. All that said, Gabor and Nice (2004), by using molecular data, have shown that the four previously recognized subspecies of the Eastern Newt lack significant differences between them. However, these authors do indicate this was a “preliminary analysis.” Habitat and Habits In Michigan, the Eastern Newt (in the adult aquatic phase) prefers small permanent ponds but also inhabits vernal ponds, sloughs, marshes, bogs, and shallow regions of larger lakes. The eft is usually found in nearby woods under rotting logs, rocks, and other shelters (MDNR, n.d., Eastern Newt). These newts prefer aquatic habitats that have a significant growth of aquatic plants. In deep ponds they may remain active during the entire year. Efts that emerge

2. Species Accounts

from breeding sites in open areas are usually found close to the site under boards or flat pieces of trash. Efts may be found walking about in the open after rainstorms. When ponds dry up prematurely, newts can become terrestrial again. In the process, their skin darkens and becomes granular again, and their tail fins shrink—a truly amazing turnabout. Reproduction and Growth In Michigan, adults breed in late winter and early spring. In southeastern Michigan, Ball (1999) collected his first breeding Eastern Newts on March 3, 1997, and his last ones on April 9, 1997. The peak of the breeding season was in early April. Males dominated females by seventy-seven to thirty-five during the 1997 season. The following account of courtship behavior in the Eastern Newt is condensed from the account by J. W. Petranka (1998, 454) that he synthesized from several authors. Sometimes an abbreviated form of courtship occurs in Eastern Newts. In this short courtship, males move slowly about the ponds searching for females. If a female stays close to a male when approached, he performs a short lateral display in front of her that consists of undulating his body and tail. If the female nudges the tail of the male with her snout, the male deposits a spermatophore or two and the female picks these up with her vent. In laboratory trials, this short courtship occurred about 30 percent of the time. If the female is unresponsive to the body and tail undulation, the male quickly moves over her and grabs her with his large rear limbs. The pair may be joined for several hours as the male alternates between rubbing the female with his forelimbs and with the sides of his head where specialized glands are located. At the same time the male curls his tail forward and fans it for several seconds, sending his cloacal secretions toward the nostrils of the female. This fanning can last for more than an hour, when the courtship becomes even wilder. In the next phase, the male goes into contortions that jerk the female about while his strongly everted cloaca presses against her back. This phase lasts about ten minutes. Then the male releases the female and moves just in front of her. As he moves forward he raises his tail, everts his cloaca, and undulates his body. At this point the female follows the male, often lightly nosing his tail or cloacal region. The male then deposits a

spermatophore. One or two additional spermatophores may be deposited if the female noses the head of the male again. Once the sperm is deposited, the male orients his body sideways so as to put the female’s cloaca in correct alignment with the sperm cap, which she picks up. The spermatophore is about 4 to 7 mm (.16–.28 in.) high and has a broad base and an abruptly narrowing stalk with a sperm mass at the top (Bishop 1941). Bishop (1941) reported that when females deposit eggs they grasp the substrate with their hind legs, push their thighs together, and squeeze the eggs out one at a time. Relative to the oviposition and incubation of Notophthalmus viridescens in the Great Lakes region, Harding (1997) stated that most egg laying is done in April and May and that females deposit from a few dozen to three hundred or more eggs over a period of several days or weeks. These eggs are usually attached singly to plants or other objects. The incubation period lasts from about two to five weeks, depending on the water temperature. At hatching, the minute larvae measure about 7 to 9 mm (.28–.35 in.) in length. The larvae of Eastern Newts in a New York pond were found to be generalists that fed on the material that was most accessible and available. Their diet consisted mainly of ostracods, copepods, chironomid larvae, snails, and fingernail clams along with some miscellaneous food items, including beetle larvae, mosquitoes, and water mites (Hamilton 1940). P. H. Pope (1924) found that larvae of this species sometimes eat algae, and older larvae feed primarily on invertebrates, using both visual and chemical resources in the process. The larval period of Eastern Newts lasts about two months in New York (Bishop 1941). When larval density in a pond is high, the animals may grow at an average rate of 5 mm (.20 in.) total length per month; when the density is low, they may grow at an average of 11 mm (.43 in.) in total length per month (Noble 1929). Diet The diet of the aquatic newt stage in Michigan, according to Ruthven et al. (1928), consists of small mollusks, crustaceans, worms, and tadpoles. Harding and Holman (1992) reported that Michigan newts feed on small aquatic invertebrates, such as mosquito larvae and pupae, as well as the eggs and larvae of other amphibians. Efts (and terrestrial adults) are said to eat insects,

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The Amphibians and Reptiles of Michigan

worms, and small snails. Harding (1997) reported that in the Great Lakes region, adult Eastern Newts feed upon crustaceans such as fairy shrimp, cladocerans, and copepods; insect larvae such as mosquito and midge larvae; and mollusks such as fingernail clams and snails. He also reported that these newts eat the eggs and larvae of other amphibian species. Although the larvae and aquatic adults have a highly developed sense of smell, the eft form relies more on sight when feeding (P. H. Pope 1924). The efts of both subspecies feed on invertebrates in the leaf litter, especially after rains when invertebrates become active. Efts often assemble near rotting mushrooms and other places where invertebrates concentrate. Immature efts as well as adults have similar diets except that the adult forms have a tendency to take larger prey (MacNamara 1977). Predation and Defense Toxic secretions from poison glands in the skin can be produced in all phases of development of Notophthalmus viridescens. The red eft phase (first terrestrial phase) is the most toxic and most highly colored. The secretions range from being unpalatable to some would-be predators to lethal for others. Hurlbert (1970) has shown through “feeding trials” that Eastern Newts are more acceptable as food to nocturnal or aquatic predators than to daytime terrestrial predators. Some predators that have consumed one phase or another of Eastern Newts in Michigan and other states include smallmouth bass (occasionally), Western Lesser Sirens (on larvae), American Bullfrogs, Painted Turtles, Eastern Snapping Turtles, and Eastern Hog-nosed Snakes. One published record reports that a Boy Scout ate several efts wrapped in bread with no harmful effects to the boy (H. E. Evans 1947). Predatory animals that will not eat Eastern Newts include most freshwater fishes, American Toads, Gartersnakes, raccoons, killdeers, and red-tailed hawks. Interaction with Humans Harding (1997) reported that Eastern Newts are frequently collected for the pet or biological supply trade but that data on the volume or effect of this collecting in the Great Lakes region is not known. As most freshwater fish are repelled by Eastern Newts, this is one species

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that can live alongside fish in farm ponds thick with aquatic vegetation as well as constructed backyard pools, water gardens, and ponds. Beaver reintroduction has likely provided more habitats for Eastern Newts. Behavioral Characteristics Both efts and terrestrial adult Eastern Newts engage in a spectacular warning posture called the unken reflex or posture. The very toxic red efts of Notophthalmus viridescens viridescens are more likely to engage in the unken reflex than the terrestrial adults. When Eastern Newts were threatened with a simulated predator attack, only about 15 percent of adults compared with about 36 percent of the efts assumed the unken posture (Ducey and Dulkiewicz 1994). The unken posture in N. viridescens happens this way (see also Petranka 1987): When terrestrial adults of either N. v. louisianensis (the subspecies that occurs in most of Michigan) or N. v. dorsalis (a North and South Carolina subspecies) are disturbed in the field, they first close their eyes and retract them inward. The head and tail are then bowed upward to the extent that the head touches the tail. By doing this, they display their brightly colored belly, which is a warning to the would-be predator. Population Health Eastern Newts are not considered rare in Michigan. One of the competitive edges that the species has over other Michigan salamanders is that freshwater fishes almost never eat the larvae or aquatic adults of N. viridescens. Connections between upland and wetland habitats are essential for the survival of this species because it has multiple life stages that require both aquatic and terrestrial habitats.

Family Sirenidae The sirenids have elongate, eel-shaped bodies that range in size from the diminutive species of Pseudobranchus to Siren lacertina, which reaches a length of about a meter (3.8 ft.). The species of this genus have external gills and other larval characteristics, such as gill slits and the lack of eyelids. Sirenids have a horny beak that takes the place of maxillary teeth in the upper jaw. They lack hind legs, and the front legs are relatively tiny, with four toes on each leg. Males do not produce spermatophores.

2. Species Accounts

Pseudobranchus and Siren, both with two species, are the only genera in the family. Pseudobranchus species have a composite range of Florida, southern Georgia, and southern South Carolina. Siren species have a composite range of the southeastern United States except for the Appalachian region west to eastern Texas and north to northwestern Illinois, northwestern Indiana, and southwestern Michigan.

Siren intermedia nettingi Goin 1942 Western Lesser Siren Identification The characters given for the Family Sirenidae and the genus Siren in the introduction to the Sirenidae will help you easily distinguish Siren intermedia nettingi from any other salamander in Michigan. Some other characters that may be used in the identification of this species are provided by Harding (1997). The snout is rounded, the head is wider than the neck, and the eyes are reduced in size. The species is brown, dark gray, or olive in color and usually has scattered dark spots or flecks. Some specimens appear to be almost black. The belly is gray and may have light spots. The adult length of these animals ranges from 180 to 500 mm (7.1–19.7 in.). General Distribution Siren intermedia occurs from the southeastern United States (other than the Appalachian region) west to eastern

Fig. 51. Western Lesser Siren (Siren intermedia) from Florida. Photograph by James H. Harding.

Fig. 52. Adult Western Lesser Siren (Siren intermedia nettingi). This is the form that has been found in Michigan. From C. H. Pope (1944), courtesy of the Chicago Natural History Museum.

Texas and north to northwestern Illinois, northwestern Indiana, and southwestern Michigan. Michigan Distribution Siren intermedia occurs in only two counties in southwestern Michigan, Van Buren and Allegan, just one county away from the Indiana border. Since this species is not known in the upper tier of counties of Indiana, except for a record in extreme southwestern Porter County (Minton 2001, 102, map), I suggest that S. intermedia is part of a relict population in Michigan that may have extended farther north along the Traverse Corridor (a warm belt along coastal Michigan) during the Hypsithermal Interval. I believe these are natural rather than introduced populations of this species because (1) although isolated they lie close to natural populations in northwestern Indiana, (2) they represent the northward-extending subspecies S. i. nettingi, and (3) the published habitat of the Van Buren County specimens is typical of the species and the subspecies. Unfortunately, I have not been able to find published information on the Allegan County specimens. The specimens found in Van Buren County came from a three-hundred-acre lake that had quiet, shallow bays with thick aquatic vegetation (Williams 1961), which apparently were suitable habitats for this species. The day before two of the sirens were recovered, the

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The Amphibians and Reptiles of Michigan

lake had been treated with rotenone to reduce the carp population. These sirens measured 223 and 151 mm (8.8 and 5.9 in.) in total length. Williams reported that several additional sirens were found dead at the lake a week after the rotenone treatment. The Van Buren County lake where the sirens were taken drains to the Middle Fork of the Black River in Allegan County. Sirens have not been seen in Michigan for many years (MDNR, n.d., Western Lesser Siren). Geographic Variation Nothing has been published on possible geographic variation between the northwestern Indiana and the southwestern Michigan specimens of Siren. Habitat and Habits Minton (2001, 102–3) reported that “these singular salamanders are largely aquatic and prefer warm, quiet, shallow water with mucky bottom and plentiful aquatic vegetation. In Indiana they have been reported from drainage ditches, stock ponds, bayous, swamps, and shallow inlets of lakes. Sirens can endure dry periods by entering crayfish burrows or burrowing into the mud.” On this subject, C. H. Pope (1944, 63) had earlier stated that “a number of specimens [of S. i. nettingi] that had followed crayfish burrows to depths varying from eighteen to forty inches in Franklin County, Illinois, late in December, were active enough to try to escape when handled. Their home had been drained of its shallow water since midsummer, so they had circumvented cold as well as dryness by entering mud.” Cagle and Smith (1939) reported an assemblage of 138 of these Sirens in about seven inches of water in a culvert near Herrin, Illinois, on January 1 and 2; the animals were inert and their stomachs were empty. Minton (2001) suggested that Siren intermedia probably leaves the water voluntarily from time to time, as it has been found in artificial ponds that were never connected to the natural habitats of this species. Blatchley (1900) saw many Sirens dug up by a farmer plowing lowland that had been drained the preceding year. They have also been found in and under logs. If the mud on the bottom of a pond dries out, Siren intermedia is able to conserve water by forming a cocoon around itself that covers all of its body except the mouth. The cocoon is thought to be derived from layers of epidermis as well as secretions from glands in the skin (Harding 1997).

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In 1962 some students and I located Siren intermedia nettingi in an unusual situation. The setting was the upstream end of a large tile draining an actively flowing stream in Union County in southern Illinois. Here we saw small black sirens from time to time darting out of large masses of stationary watercress (a pungent perennial herb introduced from Eurasia). All of the sirens were swimming against the current. We picked up adherent masses of watercress with a small hand dredge several times and obtained about fifteen sirens. All of them measured about 145 mm (about 5.7 in.) in total length. Reproduction and Growth Breeding and courtship patterns in both species of siren are mainly unknown. What is known about this subject in Siren intermedia mainly comes from Florida and Louisiana. Godley (1983) reported that ovulated or spent females in Florida tend to have bite marks on their bodies and suggested that the biting was by courting males. On the other hand, bite marks have been found on both males and females in December, January, and February in Louisiana (Raymond 1991). In Illinois and Texas, Siren intermedia breeds in the spring, with about two hundred to seven hundred eggs laid by each female (Davis and Knapp 1953). In northeastern Arkansas, Noble and Marshall (1932) found the hollow nests of this species on the bottom of ponds on April 8 and 10. The embryos in the eggs were reported to have been in an advanced stage of development. In the species as a whole, newly laid eggs are 2.5 to 3.0 mm (.10–.12 in.) at their greatest width and are surrounded by three jelly envelopes. Minton (2001, 103) reported that “small larvae were collected May 31 near Terre Haute (Indiana) in a small pond connected with Otter Creek. A 65 mm specimen was collected in northern Indiana on September 20.” Davis and Knapp (1953) reported that both male and female S. i. nettingi in a farm pond in Texas grow to about 130 and 110 mm (5.1–4.3 in.) in snout-to-vent length, respectively, during their first year of life. Females become sexually mature during their second year, when their snout-to-vent length is about 150 mm (5.9 in.). Diet In the Great Lakes region, Harding (1997, 47) reported that “sirens eat a variety of invertebrate prey, including

2. Species Accounts

small crustaceans, insect larvae, snails, and worms. Quantities of algae and other aquatic plants have been found in their stomachs, but this material is probably swallowed accidentally when these salamanders feed on small animals in thick vegetation.” Petranka (1998, 487) somewhat refined this information: “The large amount of debris in specimens may reflect a common feeding behavior that involves gulping in bottom debris or plant material, then filtering out food and other items as water is passed through the branchial openings.” Siren intermedia will often cannibalize its own eggs (see Collette and Gehlbach 1961; Scroogin and Davis 1956).

General Remarks Hints for the would-be herpetological hero: 1. Unless you have skin like a toad, do not try to grab a siren in the water, as they are too slimy and strong to hold; use a hand net or a small seine. 2. Look for them at night when they are active. 3. Do not try listening for yelping or clicking noises because they make these sounds underwater. 4. If you encounter this species, please report it to the Michigan Herp Atlas Project right away.

Predation and Defense The natural predators of this species are not well known. Since American Alligators are known to feed regularly on Siren lacertina (Delany and Ambercrombie 1986), one might assume that at least small ones would feed on S. intermedia. As I am not aware of any particularly noxious skin secretions in this species, I would imagine that such predators as freshwater fishes, American Bullfrogs, Watersnakes, and wading birds would take their toll on Lesser Sirens. Petranka (1998) suggested that the nocturnal habits of S. intermedia minimize the risk of predation of such animals as wading birds and fishes.

Order Anura

Behavioral Characteristics Lesser Sirens make yelping or clicking sounds. They yelp when they are bumped, butted, or bitten by other sirens. This is a distress or alarm signal. Both S. i. intermedia and S. i. nettingi produce clicking sounds just before or after they leave their burrows on the way to the surface of the water to gulp air (Gehlbach and Walker 1970). Lesser Sirens living close to one another in underwater burrows frequently click and jerk their heads at the same time. These clicks are thought to be intraspecific communication devices related to the defense of burrows. Population Health As previously stated, these salamanders have not been seen in Michigan for many years. They are listed as a Species of Special Concern. Since they are nocturnal and otherwise secretive in their habits, it is possible that populations still exist in the state. Anyone who can find this animal in a natural situation in Michigan will instantly become a herpetological hero.

The differences between the frogs and toads of Order Anura and the salamanders of the Order Caudata were briefly discussed at the beginning of the Caudata section. When the term “frog” appears in the general sense on the following pages, I am using it as a shorthand term for the Anura (both frogs and toads), as is the common practice in herpetology. Frogs occur worldwide except for the extreme northern latitudes, Antarctica, and most oceanic islands (Frost 1985). The greatest diversity of frogs occurs in the tropics. Only six families of frogs occur in the temperate parts of North America (Duellman and Trueb 1986). Three families of frogs presently occur in Michigan: the Bufonidae, Hylidae, and Ranidae.

Toads Family Bufonidae True toads, the Bufonidae, occur worldwide in temperate and tropical regions, except for the Australian-Papuan region, Madagascar, and Oceanic regions. The giant Cane Toad has been introduced into many tropical and subtropical regions. The Bufonidae forms a huge anuran family with thirty-one genera and about 370 species. Bufo—the only genus of the family that occurs in Michigan—has about 211 species throughout the world (Duellman 1993). Most true toads have thick, granular skin, either with or without wartlike bumps. Some genera, including Bufo, have parotoid glands, which are a pair of swollen poison glands, one on each side of the body just behind the eyes. Most bufonids have either terrestrial or burrowing habits.

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The Amphibians and Reptiles of Michigan

Note that some herpetologists have started using the genus Anaxyrus for these toads, following Frost et al. (2006). In this book, I have retained the traditional use of Bufo, pending wider acceptance of this controversial change.

Bufo americanus americanus Holbrook 1836 Eastern American Toad Identification This toad, Bufo americanus americanus, and the account of the one that follows, Bufo fowleri, are the only anurans in Michigan that have parotoid glands (see the previous section). Both species have rough, warty skins and short legs. In Michigan, the color of the Eastern American Toad may be brown, reddish brown, tan, or olive. They usually have dark spots on the back that contain only one or two of the larger wartlike bumps on the top of the body. The belly and throat area is white or pale yellow, often with dark spotting. Some species in northern Michigan and some on the islands of the Lake Michigan Archipelago are very large. The call of Bufo americanus americanus is an extended—up to thirty seconds—musical trill, a much different sound from

that made by Bufo fowleri. The fact that the two species occasionally hybridize complicates the identification process. Ruthven et al. (1928) described the anuran larvae, and I have included a modified version here. They noted that the larvae of Bufo americanus americanus have a round body that is black and stippled with gold. The tail is long and narrow, and its upper and lower edges are compressed to form a translucent gray fin. Two rows of teeth occur in the upper lip and three rows in the lower. The upper and lower lips bear papillae (small nipple-like protuberances) that fold in at the sides of the mouth. The anal opening is in the middle of the body. General Distribution The composite range of Bufo americanus (the subrange of the other subspecies, B. a. charlesmithi, is discussed later in this account) is from the Maritime Provinces of Canada to southeast Manitoba, south to eastern Kansas, Mississippi, and Louisiana. Isolated populations occur in North Dakota and Newfoundland. Michigan Distribution Bufo americanus americanus occurs in every county in Michigan. It occurs on Isle Royale and Drummond,

FIG. 53. Eastern American Toad (Bufo americanus americanus) from Ingham County, Michigan. Photograph by James H. Harding.

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2. Species Accounts

Bois Blanc, and Charity Islands. In the Lake Michigan Archipelago, it occurs on Beaver, Garden, High, Hog, North and South Fox, North and South Manitou, Squaw, Trout, and Whiskey Islands. On the Detroit River and Lake Erie, it occurs throughout most if not all the islands. Geographic Variation Distinct populations within B. a. americanus in Michigan have not been widely discussed, other than the very large Eastern American Toads found in the upper part of Michigan and adjacent islands and recently documented accounts in the islands of the Detroit River. Starting with the Beaver Archipelago, Gillingham (1988, 91) states that “significantly, the toads found on Beaver (and the surrounding islands) very often tend to be of larger size than those found on the mainland.” This “gigantism” is often typical of island organisms and in this case may result from greater longevity combined with the toad’s habit of lifelong growth. Individuals living on islands may have a greater opportunity to grow older than the average toad found on the mainland. Lack of predation may contribute to their longer lives on these islands. I have captured toads on both Beaver and Garden Islands that were more than six inches long. Long (1982, 1993) suggested that these large toads represented a new subspecies referred to as “Bufo americanus alani.” Placyk and Gillingham (2002) argued that other than the size differences little suggests that these island toads represent a separate subspecies of the Eastern American Toad. No morphological, life history, or behavioral characters differ from those of Bufo americanus americanus. The Committee on Scientific and Standard English Names (see Crother 2008) has not recognized this subspecies as valid. Possibly molecular studies could indicate otherwise. Relative to “giant toads” on the mainland of the upper Lower Peninsula of Michigan (Holman and Holman 2003), Emmet County is the most northwestern county in the Lower Peninsula and thus at once becomes the northernmost and most prominent of the series of western bulges of the mainland into Lake Michigan. This county was cut off from the mainland by a wide channel in the Pleistocene Ice Age and was cut off once more, probably for the last time, about four thousand years ago during the so-called Nipissing Lake

stage. About three thousand years ago, Emmet County had mainly reconnected with the mainland. Shortly before and after World War II, I looked for amphibians and reptiles in the Emmet Island part of Emmet County while vacationing with my parents. There I was delighted to find the largest Eastern American Toads I had ever seen. Most of the toads I found were four or more inches long, and one old male that dwelled in the vicinity of our cabin was as large as the “typical” 10–15 cm Marine Toads I was to see much later in life in Mexico. A very small southern B. americanus that occurs from southern Indiana and Illinois south to western Tennessee and northern Louisiana, and west to northeastern Texas and eastern Oklahoma is recognized as the subspecies Bufo americanus charlesmithi Bragg (Dwarf American Toad) by Crother et al. (2008) based on studies of mitochondrial DNA. Habitat and Habits Eastern American Toads, according to Harding and Holman (1992) and Wright and Wright (1949), are ubiquitous in their choice of habitats. In Michigan they are typically found in open woodlands and along woodland edges, but they can also be found in meadows, at the edge of marshes, in vacant lots of small communities and gardens in the suburbs of larger cities, and around the margins of cultivated areas on farms. Objects used for shelter may include stones that have been placed in gardens, boards, logs, woodpiles, heaps of cut grass, and stacks of tarps. Ponds or standing water of some kind are necessary for the reproduction and survival of this species. During their winter hibernation, American Toads will seek out areas with soft soil to burrow into to avoid freezing temperatures. Ruthven et al. (1928, 34) stated that “during the day it [B. a. americanus] sits in a burrow, which it makes by backing into the soft earth or dense vegetation, and sleeps. It is so protectively colored that it is usually very hard to distinguish from the clods of earth or the background of partially shaded vegetation in its usual haunts.” Wright and Wright (1949) observed that when cold weather arrives, B. a. americanus may dig farther backward into its summer quarters or may utilize another site for its hibernation. During its active time in the spring, winter, and fall, the Eastern American Toad is mainly active at night.

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The Amphibians and Reptiles of Michigan

Bufo a. americanus was found hibernating at depths of 15.2 to 17.8 cm (6–7 in.) and as deep as 53.3 to 55.9 cm (21–22 in.) in an excavated ant mound hibernaculum in Washtenaw County, Michigan, on February 25, 1951 (Carpenter 1953). Reproduction and Growth Ruthven et al. (1928) made observations of Eastern American Toads over a period of years in Ann Arbor, Michigan, and found that the toads emerged after the first week in April, generally from April 10 to April 28. The males emerged first and appeared to outnumber the females in the ponds that were observed. The researchers pointed out that, when disturbed, the males made a peculiar chirping sound somewhat like the scolding of a chicken. They reported that these males called during this early part of the season but that isolated calls could also be heard in the summer, especially on wet nights. In Michigan and the Great Lakes region, Eastern American Toad males move to ponds, ditches, sloughs, and floodings from early April to early May and begin to call from the shoreline or shallow waters at the breeding site (Harding 1997; Harding and Holman 1992). The first movement to breeding sites is often initiated by rainy, humid conditions correlated with warm evening temperatures. My field notes indicate that in the Lansing area this activity begins about April 15. Most breeding occurs over a period of between ten to fourteen days. If cold weather interrupts this breeding activity, breeding may begin again when the weather moderates. Breeding can extend until June or July from time to time. This may relate to the summer calls on wet nights mentioned by Ruthven et al. The occasional hybridization between the Eastern American Toad and Fowler’s Toad may relate to this occasional late breeding by B. a. americanus, as Fowler’s Toad characteristically breeds about a month later than the Eastern American Toad. I have never seen the two species of toads together in the same breeding pond in Michigan, but Minton (2001, 114–15) stated that “in normal years, Fowler’s Toad does not begin to call until the breeding season of the American Toad is almost over, but I have seen both species in amplexus (joined together) the same night in the same pond in southern Indiana during early May.”

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The Eastern American Toad call is given with the throat sac inflated. The first males to call attract both females and other males to the pond. Males will not only try to grasp females but other male toads as well. The grasped males give a chirping release call (the chicken-like chirp unexplained by Ruthven et al.) accompanied by body vibrations. This indicates to the grasping male that he has chosen the wrong sex, and he usually releases the other male forthwith. When a female is successfully grasped (amplexed), the paired toads usually move to another part of the pond, probably to avoid attempts by other males to horn in. Female toads drown from time to time when clasped by more than one male. During amplexus the female lays from about two thousand to more than twenty thousand eggs. The large number of eggs probably explains the hundreds of newly metamorphosed baby toads that one sees from time to time in Michigan as well as other places in the eastern United States. This undoubtedly reflects years when conditions are just right for egg laying and larval development. Eastern American Toad eggs emerge from the female in two gelatinous strings. The strings of eggs may be wound around underwater branches or simply left on the bottom of the pond. The tadpoles hatch in two to fourteen days, depending on the water temperature at the site. The tadpoles are black and during the day form schools that seek warm areas where food is abundant. Food items eaten by Eastern American Toad larvae include algae, diatoms, and other planktonic forms of life, soft plant remains, and carrion. Toad tadpoles are avoided by some predators, but they are eaten by many species of fish and aquatic insects, including diving beetles. These tadpoles grow quickly in good weather and transform into toadlets within about six to ten weeks. These toadlets are very tiny, ranging in length from about 8 to 13 mm (.31–.51 in.). It takes two or three years for these tiny toadlets to achieve sexual maturity, and relatively few make it, although marked Eastern American Toads have survived in the wild for more than ten years. Diet Eastern American Toads eat an amazing variety of small animal life. I imagine the giant toads on the islands of the Lake Michigan Archipelago and on the tip of the

2. Species Accounts

Lower Peninsula might be able to eat small snakes and even small mammals, such as shrews and mice, although I am unaware of published material on this subject. Normal-sized Eastern American Toads consume a plethora of insects and insect larvae, spiders, centipedes, millipedes, snails, slugs, and earthworms. In reference to the capture of prey by Bufo a. americanus in the Chicago area, C. H. Pope (1944, 78–79) stated that “toads often approach their prey stealthily before the lightning-like action of the sticky, elastic tongue makes it vanish as if by magic. A forward lunge co-ordinated with a two-inch reach of the tongue can do the job at a surprising distance. Long wings and bodies introduce difficulties readily overcome by skillful use of the hands after tongue and jaws have made a good start. A motionless animal is seldom noticed, and unsuitable objects in motion are often slapped with the tongue in vain.” Pope went on to state that two captive specimens got into complications when fed together. One aggressive individual, attracted to the movement of the other’s nostrils, would give the other individual a violent lick that would spoil her appetite. Pope speculated that one might almost conclude that the act was intentional, since it allowed the aggressor to get all the food. Relative to toads slapping unsuitable objects in vain with their tongues, Roster and Gillingham (1994) used video-simulated prey (fake animated crickets moving around on a TV screen) to try to determine whether differences in prey-catching behavior existed between frogs and toads. What they found was that both Bufo americanus (American Toads) and B. terrestris (Southern Toads) oriented toward the animated crickets more frequently than did Northern Green Frogs (Rana clamitans), but that once orientation occurred, there appeared to be no difference in the frequency of attack by either the toads or the frogs. Predation and Defense Eastern American Toads have several behavioral and chemical defenses against would-be predators. When an enemy approaches, the toad may lower its snout and hunch its body forward. This not only makes the animal seem larger but also presents its poisonous parotoid glands to the attacker. Eastern American Toads swell up when a predator attempts to swallow them, and a watery urine may be produced. This urine, by the way, is not

poisonous and does not form warts on humans. But the whitish parotoid poisons produce steroids that can affect heart function as well as blood pressure. These poisons can produce illness or death in small mammals that chew on or swallow the toads. Even though these defense mechanisms undoubtedly ward off many predators, some predators regularly consume Eastern American Toads. These include Eastern Gartersnakes, Eastern Hog-nosed Snakes, Common Watersnakes (observed by the author), hawks, herons, and some waterfowl. Raccoons are said to feed on toads by eating them from the belly side, thus avoiding the poisonous glands on the sides and back. Studies at Van Pond north of Pellston, Emmet County, Michigan, by Heinen (1994a) showed that newly metamorphosed Eastern American Toads responded with stereotypical crouching and lowered rates of motion to the sight of any live snake, including known toad predators, such as Eastern Gartersnakes, and non-toad predators, such as Northern Ring-necked Snakes and Smooth Greensnakes. Toads that did not move and remained crouched in the presence of actively hunting Eastern Gartersnakes were less likely to be captured than those that moved or were upright, or both. Hungry toads on the move were more likely to be captured by Gartersnakes than stationary toads. Relative to the significance of dark or light color changes in newly metamorphosed Eastern American Toads from Van Pond, Heinen (1994b) found that toads kept on dark substrates could darken and those kept on light substrates could lighten. Hunting Gartersnakes caught more dark-matched than light-matched toads on a light-colored, sandy background. But there was no difference in rates of capture between dark- and lightmatched toads on a dark-colored, topsoil background. Dark-matched toads tended to move more often than did light-matched toads on the light background. Interaction with Humans The value of Eastern American Toads as a predator on insects harmful to farmers’ interests is legendary and perhaps has sometimes been exaggerated. N. Miller (1909) concluded that the value of a single toad was worth about five dollars per year to farmers and commented to the effect that other estimates were as much as twenty dollars per year. Given what the inflation

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The Amphibians and Reptiles of Michigan

of those dollars would be today, there should be a toad monument in the front yard of every centennial farm in Michigan. Whatever the value may actually be, there is no doubt that toads are important for insect control. Miller dissected the stomachs of many American Toads and came to the conclusion that a toad of ordinary size (36 grams in weight) eats insects at an average rate of twenty-six per day from May through August, which would be 137 grams (4.8 ounces) of insects consumed during the peak of toad feeding activity. Toads are very adaptable to habitats that are far from pristine, but degradation of breeding sites in urban parks, gardens, and farming areas can cause remarkable declines or even extirpation of these animals. In the last fifteen years, I have seen a dramatic decline of breeding populations of Eastern American Toads in vernal ponds on Michigan State University property. The ponds are still there, but for some reason the toads are not.

Bufo fowleri (Hinckley 1882) Fowler’s Toad Identification The best way to distinguish Bufo fowleri from Bufo americanus, described in the preceding account, is to show up at a toad breeding site in May or June and listen to the calls. The call of Bufo fowleri is an eerie, mournful “waaaaaaaaaa” that lasts from two to seven seconds and sounds as if it should be emanating from a misty swamp in Transylvania. Most people I know subjectively consider the Eastern American Toad call sweet and the Fowler’s Toad call annoying. But I prefer the call of Bufo fowleri, as it brings back nostalgic memories of warm, sweet-smelling, early summer evenings in the country, gazing at a yard lighted only by glowworms and fireflies.

Behavioral Characteristics For the behavioral characteristics of Eastern American Toads, see the “Reproduction and Growth,” “Diet,” and “Predation and Defense” sections of this account. Population Health Eastern American Toads are still relatively common in Michigan, although at least some populations are believed to be in decline. General Remarks C. H. Pope (1944, 80) said, “No amphibian pet is more quaint and interesting than a toad.” I am not encouraging anyone to put toads in a terrarium, but you may have toads that inhabit your yard or garden plot. In that case, do some toad watching. It’s great fun. Some of my friends in England put half-tiles or brick shelters near their gardens where the resident toads (Bufo bufo) feed on insects. The toads soon learn to occupy these shelters, and may be watched emerging, eating insects, and then returning to their human-supplied shelters. Some people have even been able to follow them to the breeding sites, especially if they have made shallow breeding ponds in their backyards.

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FIG. 54. Fowler’s Toad (Bufo fowleri) from Allegan County, Michigan. Photograph by James H. Harding.

If you do not have access to the recorded calls of both species of these Michigan toads (although check availability with the Frog and Toad Calls link on the U.S. Geological Survey website for the Amphibian Research and Monitoring Initiative: Midwest Region), or you cannot get to the breeding sites of both of them, you have your work cut out for you trying to identify them. I have read many accounts about how to tell these species apart, but all are rather difficult to use because the species are so similar and their markings so variable. The one classic character in all these accounts is that the larger black spots on the back of B. americanus usually

2. Species Accounts

encircle only one or two of the larger wartlike bumps; the larger black spots on the back of B. fowleri usually encircle three or more of the larger bumps. Another character is that the whitish or yellowish belly of B. americanus usually has more dark spotting on the belly than the whitish or yellowish belly of B. fowleri. Other characters given by Wright and Wright (1949) to separate these species (BA = B. a. americanus, BF = B. fowleri) are: 1. Wartlike bumps on body of BA larger and less numerous than on BF. 2. Parotoid glands of BA broad, not separated by the distance of their own length; parotoids of BF narrow and frequently separated by the distance of their own length. 3. Belly of BA usually very spotted; belly of BF usually not spotted or with a dark breast spot in its middle. 4. A light line on the back rarely present on BA, and when present is very irregular; such a light line always present on BF. A character that separates the two species pointed out by Ruthven et al. (1928, 36) is that “[B. fowleri] is a much more agile, alert, and delicately formed animal than the American toad. It jumps farther and more swiftly and is in general more frog-like in behavior.” General Distribution Bufo fowleri occupies a large variety of habitats on the eastern coastal plain of the United States, but in inland areas it is likely to occur in sandy areas near ponds, lakes, and rivers. Today this species ranges from central New England to the Gulf Coast of the United States and west to Michigan, northwestern Arkansas, and eastern Louisiana. Michigan Distribution Fowler’s Toad does not occur in the Upper Peninsula of Michigan, and I am not aware of the occurrence of this toad on any Michigan islands. It occurs most abundantly in southwestern Lower Michigan, especially in the Lake Michigan coastal dune woodlands, where it extends up the Traverse Corridor to Manistee County. Its distribution is spotty in the south-central and southeastern part of the Lower Peninsula, and it is absent in the thumb area.

Geographic Variation No subspecies of Bufo fowleri are currently recognized, and as far as I can determine, no distinctive populations or “giant” Fowler’s Toads (as there are in Bufo americanus) have been recognized in Michigan. Habitat and Habits Fowler’s Toad can be found in open woodlands, on sand prairies and meadows, and at beaches. They also occur in both agricultural and suburban areas. They prefer sandy soils, especially along shorelines and river valleys. In western Lower Michigan (as well as northwestern Indiana), Fowler’s Toad is a characteristic species of dune habitats. This species is also more tolerant of hot weather and less tolerant of cold weather than the Eastern American Toad. Minton (2001) reported that Fowler’s Toad is found throughout Indiana, but that one species of Bufo tends to be rare where the other is common. In the suburb of Indianapolis where I grew up, Fowler’s Toad was fairly common, but I did not see or hear an Eastern American Toad there during sixteen years of observation. Reproduction and Growth Bufo fowleri breeds in warm, shallow, rather open sites, including woodland and farm ponds, floodplains, lake edges, and interdune ponds. Males migrate to these sites as early as late April or early May, but the height of breeding activity in this species is in late May and June. This is usually well after the peak of breeding activity of the Eastern American Toad. Very little has been recorded about the species’ amplexus and oviposition in Michigan. Wright and Wright (1949, 213–14) recorded the following in their field notes: “April 15, Raleigh, N.C. Fowler’s toads were still in chorus and strongly breeding, though started much earlier. The male of the mated pair has the first two fingers doubled back and dug into the axils (arm pits) of the female. Often the other two fingers may not be doubled back but lie next to the belly of the female, or sometimes these two fingers will rest on the shoulder insertion with only the first two in the axil proper. The pairs brought in were not laying at 3 a.m. but at 6:45 a.m. they were well along in oviposition. Water temperature at which they were laying is 67ºF.” Amplexus and oviposition occur later in Michigan and the Great

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The Amphibians and Reptiles of Michigan

Lakes region. C. H. Pope (1944) stated that at about the latitude of Chicago, breeding apparently begins in May and extends into July. Harding (1997) reported that migration to breeding sites by Fowler’s Toad typically occurs in late May and June in the Great Lakes region, well after the height of breeding activity in the American Toad. From about seven thousand to ten thousand eggs are oviposited in elongate gelatinous strings that closely resemble those of the Eastern American Toad. Nevertheless, use of a hand lens shows that the eggs of B. fowleri are enclosed in a single membranous tube within which the eggs are not individually separated by partitions. By comparison, the eggs of B. a. americanus are enclosed in a double-layered tube, and the eggs within are separated by partitions. The eggs of Fowler’s Toad hatch in about two to seven days. The larvae metamorphose into tiny toads that reach 10 to 14 mm (.39–.55 in.) in length after about thirty to forty days. Since Fowler’s Toad breeds later than the Eastern American Toad, the incubation temperature is higher than that of B. a. americanus, and it is not unusual for the tiny toadlets of both species to appear at about the same time. Fowler’s Toads reach sexual maturity in from one to three years. Diet Harding and Holman (1992) reported that in Michigan, Fowler’s Toads eat insects, spiders, and other small invertebrates. C. H. Pope stated that available information about the Chicago area indicated that Fowler’s Toads ate mainly insects but would not refuse other small invertebrates. He also noted that it is less fond of earthworms than the Eastern American Toad. Minton (2001) suggested no marked differences probably separate the diets of Fowler’s Toad and the Eastern American Toad, but he does point out that the more diurnal (active by daylight) habit of Fowler’s Toad may thereby cause it to eat more arthropods than the American Toad and fewer worms and mollusks. However, in suburban Indianapolis in the 1950s, I found that in the heat of late summer, Bufo fowleri began to become active just at the interface of dusk and darkness. Predation and Defense The predators and defensive behavior of Fowler’s Toad

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have been assumed to be essentially the same as those of the Eastern American Toad (Harding 1997). However, this species has been reported by C. H. Pope (1944) to “feign death by becoming immobilized in an upside down position” (see fig. 55).

FIG. 55. Fowler’s Toad feigning death in an upside-down position. From C. H. Pope (1944), courtesy of the Chicago Natural History Museum.

Interaction with Humans Both the breeding sites and terrestrial habitats of Fowler’s Toad need protection. Harding (1997, 122) pointed out that “intensive recreational use of beach and dune habitats, particularly by off-road vehicles, is detrimental to this species. Agricultural chemicals have also been blamed for the decline or disappearance of this toad in some places.” As far as I know, Fowler’s Toad has not been exploited by either the laboratory or pet trade. An old myth is that handling toads will produce warts on the hands of the handler. This is not true for any toads of the genus Bufo in North America. Nevertheless, because of their defensive skin secretions, you should wash your hands immediately after handling any amphibian. If that is impossible, do keep your hands away from your face until hand washing can be done. Behavioral Characteristics Some early studies of homing in both Bufo americanus americanus and Bufo fowleri (e.g., C. H. Pope 1944) apparently have not been substantiated. Population Health Bufo fowleri is on neither the Threatened nor the Endangered lists. It is a Species of Greatest Conservation

2. Species Accounts

Need in Michigan. There is no doubt, though, that Fowler’s Toad habitats, especially those in the dune areas of the state, have been degraded. General Remarks I worry about the correct identification of both Bufo americanus americanus and Bufo fowleri in Michigan. While looking through preserved collections of this species in the Michigan State University Museum, I have found B. a. americanus identified as B. fowleri and vice versa. Perhaps we will someday find a “litmus test” that will solve the problem. Until that happens, the best way to correctly identify each species is by associating it with its unique breeding call.

rocks being tapped together. The males of this species have a somewhat thickened pad on the inside of the thumb and a vocal sac that is pale yellow and mottled with gray, these features being most evident during the breeding season (Harding 1997). The adult length ranges from 20 to 38 mm (.79–1.5 in.) from snout to vent. The larva is dark above and finely stippled with gold. The underside is a metallic copper color. Two rows of teeth occur on the upper lip and three rows on the lower lip. The papillae on the lips are not doubled in at the corners of the mouth. The anal opening is on the right side of the body (dextral).

Frogs Family Hylidae The huge Family Hylidae occurs mainly in North and South America, the West Indies, and the Australo-Papuan region. One species group of Hyla occurs in temperate Europe and Asia, extreme North Africa, and the Japanese Archipelago. Forty-three living genera and about 719 living species were recognized in 1992 (Duellman 1993), and more of each continue to be recognized. The genus Hyla was represented by 281 species in 1992 (Duellman 1993). Hylid frogs are extremely variable in their external characters as well as size, ranging from 17 to 140 mm (.67–5.5 in.) in snout-to-vent length. Distinctive toe pads are usually present in hylids, and most are arboreal (Duellman and Trueb 1986).

Acris crepitans blanchardi Harper 1947 Blanchard’s Cricket Frog Identification This unique little frog, Blanchard’s Cricket Frog, has warty skin above and granular below, but it is moist rather than dry, as in the toads. This Acris species has small terminal discs on the toes rather than the widened toe pads that occur on arboreal hylids such as Hyla. Blanchard’s Cricket Frog has long hind legs with a dark stripe on the inner thigh. The upper surface of their bodies is brown, tan, or olive green. Blanchard’s Cricket Frogs are great leapers and tend to jump about in a random, zig-zagging, cricket-like fashion when disturbed. Their call is a series of clicks that sound like two small

Fig. 56. Blanchard’s Cricket Frog (Acris crepitans blanchardi) from Barry County, Michigan. Photograph by James H. Harding.

General Distribution The range of this frog extends from Michigan and Ohio to Nebraska, extreme eastern Colorado, and most of Texas; to the Pecos River valley in New Mexico and the Rio Sabinas valley in Coahuila, Mexico; through northern Florida and Alabama; and north to southeastern New York and Rhode Island. Michigan Distribution Blanchard’s Cricket Frog has historically been recorded in almost all the counties of the lower third of the Lower Peninsula in Michigan, with the exception of the upper part of the thumb area. I find the single record from Leelanau County hard to believe because it is so far north of the southern tiers of counties where this species has previously been recorded, but I have included it on the range map with a question mark.

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The Amphibians and Reptiles of Michigan

Geographic Variation As far as I am aware, no distinct populations of this small frog have been identified in the state. The trinomial name Acris crepitans blanchardi (Harper 1947) used in Michigan and the Great Lakes region (e.g., Harding 1997) is now not considered valid (see McCallum and Trauth 2006). Habitat and Habit Oldham and Campbell (1986) point out that Cricket Frogs are the most aquatic North American treefrog. Thus, relatively permanent bodies of water are critical for the survival of this species. In Michigan, one favorite habitat is the fenlike shores of nonacidic ponds and lakes. About the habits of this frog in the Great Lakes region, Harding (1997, 125) wrote that “these frogs usually inhabit the more open edges of permanent ponds, bogs, lakes, and slow moving streams or rivers. Where aquatic vegetation is abundant, the frogs are often seen on floating algae mats and water lily leaves; sparsely vegetated mud flats and muddy or sandy shorelines are also favored habitats.” Minton (2001, 116) reported that in Indiana “quiet, reasonably permanent water in open country is essential for this little amphibian. Transient, shallow pools are inhabited only if near a larger body of water. Typical habitats in Indiana include stock ponds, strip mine ponds, drainage ditches, marshes, and the margins of lakes and larger streams. Muddy banks with much aquatic vegetation favor this frog, but there are large populations in water-filled quarries and sand pits where there is little emergent vegetation.” I might add that I observed abundant Blanchard’s Cricket Frogs in a small, polluted, sewer-fed stream (Pleasant Run Creek) in suburban Indianapolis for years. This stream had such a bad odor in late summer that my mother forbade me to go there, yet the Cricket Frogs thrived in this environment. Acris crepitans blanchardi individuals live within a restricted area. Burkett (1984) reported that Cricket Frogs tend to have very limited dispersal; almost half of the recaptured frogs in his studies were within twenty-five feet of the spot where they were originally captured. Reproduction and Growth Blanchard’s Cricket Frogs breed from about the middle of May to the beginning of July in the Great Lakes region (Harding 1997). Breeding activity appears to

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be initiated by warm rainy conditions. Males give their distinctive clicking call during the day as well as at night, and these calls do sometimes continue into the middle of the summer. Both amplexus and oviposition take place in shallow water near the calling site. From about two hundred to four hundred eggs are laid one at a time or in small clumps. The eggs may stick to submerged plants, sticks, and other objects, or they may float at the water surface. The tadpoles hatch within a few days of oviposition and tend to be bottom-dwellers with solitary habits. The larvae mature into tiny froglets within five to ten weeks (from late June through early July in the Great Lakes region), and the metamorphs range from 10 to 15 mm (.39–.59 in.) in total length. These new frogs grow rapidly, and some reach sexual maturity in time to breed the following year (Harding 1997). Burkett (1984) found that Acris crepitans blanchardi populations shift within about a month’s time from mainly adult populations to mainly juvenile populations toward the end of the breeding season. This is because of the rapid mortality of the adults and the appearance of many juveniles during this time. He also found that the average life expectancy of Blanchard’s Cricket Frog in Kansas was only about four months, with only about 5 percent of the population surviving the winter. Because of this high mortality, only one age class was represented in each breeding population. Diet Harding and Holman (1992) report that Cricket Frogs in Michigan feed both during the day and at night. Their diet is made up of small invertebrates, mainly insects. In Kansas and Nebraska, Jameson (1947) examined the stomach contents of ninety-four Cricket Frogs and found aquatic beetle larvae to be the most common food item. Also eaten were spiders, midge larvae, muscoid flies, water boatmans, and springtails. Most feeding took place in the water, both submerged and at the surface. Predation and Defense Relative to the Great Lakes region, Harding (1997, 125) stated that “these little frogs are eaten by snakes, birds, and larger frogs. They attempt to evade enemies by leaping erratically on shore or by jumping into the water and hiding beneath vegetation or bottom debris. Vertical

2. Species Accounts

leaps of over 90 cm (35 in.) and horizontal leaps of nearly 1.2 m (4 ft.) have been reported.” Near Indianapolis, Perrill and Magier (1988) discovered that Northern Watersnakes were a major predator of Blanchard’s Cricket Frogs. They found that calling males were more often captured by the snakes than quiet males, and they suggest that the movement of the vocal sac rather than the sound it produces may be what attracted the snakes. In Indianapolis, I found that a captive juvenile Eastern Hog-nosed Snake would eat local Blanchard’s Cricket Frogs with the same gusto that it would eat young local toads of similar size. Interaction with Humans In the Great Lakes region, Harding (1997, 126) reported that “Blanchard’s Cricket Frog declined drastically in the northern portions of its range during the late 1970s and the 1980s. Many formerly healthy populations in Michigan and Wisconsin are now greatly reduced or extirpated, and the species has reportedly disappeared from known sites in Ontario (Point Pelee and Pelee Island). Population declines are reported for northern Illinois and Indiana as well, though the species remains common in the southern and western part of its range.” Blanchard’s Cricket Frogs are thought to be extirpated in Minnesota. In terms of what these changes mean about the quality of the environment in general, the Cricket Frog decline is frightening. Behavioral Characteristics For the behavioral characteristics of Acris crepitans blanchardi, see the “Predation and Defense” section of this account. Population Health Acris crepitans blanchardi is listed as Threatened in Michigan and thus taking this frog out of the wild is unlawful unless it is authorized by permit. A number of possible reasons for the recent decline of Cricket Frogs in Michigan are given on the Michigan Natural Features Inventory website and listed here: 1. The destruction of Michigan natural wetlands. 2. Pollution of the remaining wetlands. 3. Development of southern Michigan lakefront property, which has been altered for home flood protection at the cost of eliminating mud flats and vegetated shallow-water habitats.

4. Changes to cattle grazing. Hay (1998) suggested that the reduction of cattle grazing in Wisconsin reduced suitable habitat for Acris crepitans blanchardi by allowing thick vegetation to develop at the expense of open areas at the edge of ponds, and this change opened such sites to Northern Green Frogs (Rana clamitans) and other invading species. 5. Continuing use of pesticides and chemical pollutants to which Cricket Frogs may be very susceptible. Campbell (1978) reported high levels of DDE and PCB from Pelee Island, Ontario, where Acris crepitans blanchardi has recently become extirpated. In other areas, the use of agricultural and residential chemicals threaten this species. 6. Lakes and ponds deliberately or accidentally stocked with non-native game fish, which may eat both the larvae and adult Cricket Frogs. General Remarks In the suburban area of Indianapolis where I lived, Acris crepitans blanchardi thrived for years in a muddy, polluted, sewer-fed creek that wound through a golf course. I think the application of chemicals to produce grass must have been the main cause of their eventual extirpation in that habitat.

Hyla chrysoscelis Cope 1880 Cope’s Gray Treefrog Cope’s Gray Treefrog (Hyla chrysoscelis) and the Gray Treefrog (Hyla versicolor) are unique in the Michigan herpetofauna in that they are sibling (also called cryptic) species. Lincoln et al. (1982, 227) defined sibling species as “pairs or groups of closely related and frequently sympatric species [species that exist together] which are morphologically indistinguishable [cannot be distinguished on the basis of structural characters] but which are reproductively isolated [cannot mate together and produce fertile offspring].” In fact, the only way these two species can be distinguished from each other in the field is on the basis of their slightly different calls. Minton (2001, 124) stated that “the two species can be distinguished by voice, blood cell size, and chromosome

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The Amphibians and Reptiles of Michigan

count.” Hyla versicolor has twice the number of chromosomes (the so-called tetraploid condition) of H. chrysoscelis (Bogart and Jaslow 1979). Identification Both of the Gray Treefrogs in Michigan have a warty but moist skin. Their main color may be gray, brown, or green, and they can change rapidly from one of those colors to another or colors in between. Most individuals have irregular dark blotches on the back and legs and a white spot beneath each eye. The belly is white and the lower part of the hind legs and groin area is bright golden yellow. The total length of the adults is 32 to 60 mm (1.26–2.36 in.), according to Harding and Holman (1992). The tadpoles of both Gray Treefrogs are colorful. They are greenish above and spotted with gold and black. On the underside they are an iridescent pinkish gold color. The tail crest is high and extends along the back almost to the head. The muscular part of the tail is vermillion and spotted with black. The upper lip has two rows of teeth and the lower lip has three rows, the outermost row being wavy. The entire lower lip and the sides of the upper lip are bordered by papillae, but these are not folded in at the corners of the mouth. The anal opening is on the right side of the body. General Distribution The composite distribution of both Cope’s Gray Treefrog and the Gray Treefrog is from southern Maine south to northern Florida and west to southern Manitoba and central Texas. An isolated colony lives in New Brunswick (Conant and Collins 1998). Michigan Distribution Cope’s Gray Treefrog has been found in every county in the Upper Peninsula of Michigan and is unknown for Keweenaw. In the upper part of the Lower Peninsula, it has been recorded only in Leelanau County. In the lower part of the Lower Peninsula it has spotty occurrence, having been recorded in Oceana, Isabella, Gratiot, Clinton, Barry, Livingston, Van Buren, Kalamazoo, Calhoun, Jackson, Washtenaw, Berrien, and Hillsdale counties (from the records of the Michigan Frog and Toad Survey, Wildlife Division, MDNR.) It is important to note that because the calls of both species are very similar, the distribution of the Cope’s

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Gray Treefrog may in fact be much more similar to that of the Eastern Gray Treefrog. General Comments Cope’s Gray Treefrog has been recognized in Michigan since 1974, when the two call types were heard at Portage Lake State Park Campground in Jackson County, and chromosomal information later confirmed the identification made by the call analysis (Bogart and Jaslow 1979). Finding H. chrysoscelis in Michigan surprised the discoverers at the time, as the closest published record was far to the west in northern Illinois. Earlier, Ralin (1968) had indicated that Cope’s Gray Treefrog should not occur north of central Ohio and Indiana. Bogart and Jaslow (1979, 3) found that “most Michigan H. chrysoscelis occur sympatrically with H. versicolor which is widespread throughout the state.”

Hyla versicolor LeConte 1825 Gray Treefrog Identification See the “Identification” section in the Cope’s Gray Treefrog account. General Distribution The composite general distribution of both Gray Treefrogs is given in the “General Distribution” section of the Cope’s Gray Treefrog account. Michigan Distribution Hyla versicolor is known to occur in all counties in the Upper Peninsula except for Delta County, and without doubt it must occur there too. It occurs on Isle Royale and Drummond Island as well as on Beaver and Trout Islands in the Lake Michigan Archipelago. It has been recorded in almost all the counties in the Lower Peninsula, and it no doubt occurs in the very few counties where it has not been officially recorded. Geographic Variation As far as I am aware, no particularly distinctive populations of either H. chrysoscelis or H. versicolor have been recorded in Michigan.

2. Species Accounts

About Gray Treefrogs in Indiana, Minton (2001) reported that they are difficult to find even when they are plentiful because of their protective coloration and arboreal habits. He also stated that adults keep largely to the trees except during the breeding season. C. H. Pope (1944, 104), describing Gray Treefrog habitat in the Chicago area, stated that “although partial to woodlands and bushy areas, this amphibian is also found in orchards and on vine-grown buildings, fences, and walls. It may occasionally turn up in such places as wells, cisterns, and piles of leaves, and among stones. In the summer and autumn it ranges far from any breeding site, but just how far nobody knows.” Fig. 57. Gray Treefrog (Hyla versicolor) from Ingham County, Michigan. Photograph by James H. Harding.

Habitat and Habits Both species of these Gray Treefrogs occur in moist woods as well as along tree-lined shores of ponds, lakes, marshes, and swamps. They also adapt well to farmland and suburban areas. Within the city of East Lansing, Michigan, you can still hear Gray Treefrogs calling from time to time, usually from the vicinity of stopped-up house and garage gutters, where they may be able to breed. These calls can occasionally be heard well after the breeding season, especially after rainstorms. Residents of Okemos, Michigan, a suburban area adjacent to East Lansing, often report Gray Treefrogs climbing up the screens of their porches. Both Gray Treefrogs are mainly nocturnal and can be found foraging in low vegetation up to several feet high or in trees up to 9 meters (29.5 ft.) high (Harding 1997). These frogs have large toe pads that enable them to stick to smooth surfaces, such as the glass of enclosed porches. Ruthven et al. (1928) reported that the tops of old wells and cisterns are favorite hiding places. During the winter months, both Gray Treefrogs hibernate on land under logs, piles of leaves, loose housings, or in hollows and fissures in trees. During winter hibernation, the Gray Treefrogs are able to tolerate subfreezing temperatures by producing glycerol, a syrupy, colorless or light yellow liquid created from fats and oils within the body. Glycerol, which has been called a natural antifreeze, causes ice formation to occur in the extracellular spaces while keeping the individual frog cells from freezing.

Reproduction and Growth Gray Treefrogs of both species breed in many aquatic situations that include vernal ponds, marshes, fens, shallow edges of lakes, swamps, and sloughs. These frogs emerge rather early in the spring, but they usually are not noticed until the breeding season, when the voices of the males are first heard. My own observations are that breeding calls in Michigan usually begin in early to midMay and may last into June or even early July. They call mainly from dusk to midnight. C. H. Pope (1944, 102) commented that “in the latitude of Chicago, the height of breeding fervor falls between the middle of May and the middle of June but laying may take place before and after these dates. An air temperature of at least 72ºF. is required for maximum activity, although breeding may occur when the mercury stands ten degrees lower; rain and high humidity are also important factors. The eggs hatch in four or five days, depending on the water temperature.” In the Great Lakes region, if the two species are calling at the same temperature, the voice of Hyla versicolor is a loud, musical trill that lasts for one-half to three seconds; that of H. chrysoscelis is faster, harsher, and more nasal (Harding 1997). When both species are calling at the same time, the calls are readily distinguishable by most herpetologists, but care must be taken when trying to identify a species from a “single-species chorus” because temperature can affect both the pulse rate and duration of the call. Bogart and Jaslow (1979, 3) succinctly stated that “in some populations, a ‘hot’ H. versicolor male recorded on a warm night might be confused with a ‘cold’ H. chrysoscelis male recorded on a

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The Amphibians and Reptiles of Michigan

cool night.” Male Gray Treefrogs of both species usually call from open perches over the water. A long call is used to discourage rival males, and calling areas may be actively defended as well. In Indiana, Minton (2001) reported that in addition to the breeding call, Gray Treefrog males give at least two other calls. One of these is a high-pitched yelp that is a release or warning call. The second call is given by H. chrysoscelis and is a series of sharp whistles that brings to mind the call of both the Spring Peeper and Birdvoiced Treefrog (Hyla avivoca). Minton did not venture an explanation for the function of this call. Harding (1997) has observed that in the Great Lakes region noncalling male Gray Treefrogs may hide near calling males, waiting to take over his perch when he leaves. Males often stay around the breeding ponds for several weeks. Females may choose males that have the most extended and most frequently repeated calls. When males are approached by females, they give a distinctive courtship call that is longer than the previous advertisement call. During amplexus, the female deposits from about one thousand to two thousand eggs that are divided into loose masses of about fifteen to forty eggs. The eggs are mainly attached to plants or other material near the surface of the pond. The larvae hatch within about a week, and metamorphosis takes about six to eight weeks, depending on the elements. The metamorphs are tiny animals about 15 mm (.59 in.) or so in total length. In Michigan they are usually sexually mature by the completion of their second winter. A. H. Wright (1914) made interesting comments about mating, egg deposition, and egg structure in Gray Treefrogs in New York. He reported that the male mounts his mate and grips her in the armpits with his front limbs. As the mated pair floats free or is partly buoyed up by stems and leaves, the male fertilizes the eggs beneath the water in lots, which number from four to forty. At the same time a lot is fertilized, the female raises her rear end so the eggs spread out at the surface of the water. The transparent “mucous” surrounding the eggs then swells to form a mass that usually becomes attached to stems or leaves. Within just a few seconds, this process is repeated one or two times before a two- or three-minute rest period occurs. About an hour is spent in this deposition

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of fertilized eggs, but the two frogs may stay in amplexus for several hours. Wright goes on to explain that the transparent mucous that holds the eggs of one mass together is in a loose form and that each egg within is further enclosed by two transparent envelopes. The outer of these envelopes is about ¼ inch in diameter and clings to the mucus. The eggs themselves are yellow or cream in color at one pole and brown at the other, and they are tiny, about ¹⁄³² inch in diameter. C. H. Pope (1944) reported on activity within the egg by the embryo, escape from the egg, and the growth and metamorphosis of the larva (presumably in the Chicago area). The embryo actually becomes active in the egg long before hatching and may make violent movements. From about ten to sixty minutes before it emerges, the embryo lies with the side of its head pushed up against the wall of the capsule. It rotates its ciliated head against the capsule, a motion that is accompanied by a secretion from the embryo’s frontal gland. This activity weakens the capsule until its wall gives way and the embryo breaks free to become a larva (tadpole). A larva is only about 6.35 mm (.25 in.) long upon hatching and is an excellent swimmer from the start. It has small adhesive organs (holdfasts) that are seldom used. External gills are developed a day or two after the tadpole hatches but are resorbed within a few days. The larvae of the Gray Treefrog reach a maximum length of 50.8 mm (2 in.). They metamorphose in about 1.5 to 2 months at a length of about 12.7 to 19.1 mm (.5–.75 in.). The new frogs are green above and have no markings. Diet Ruthven et al. (1928) reported that in Michigan, Gray Treefrogs eat insects and larvae that they search for at night. Harding (1997, 36) stated that in the Great Lakes region “insects and their larvae form the bulk of the adult Gray Treefrog’s diet, along with spiders, mites, harvestmen, and snails. The tadpoles consume algae and other vegetable matter, either by filter-feeding at the surface or by rasping food off plants or the bottom substrate.” Minton mentioned that Indiana Gray Treefrogs may be seen catching insects near lights. He also makes the good point that “there is a general belief that these frogs (H. chrysocelis and H. versicolor) feed mostly on arboreal insects, but there is little detailed

2. Species Accounts

information. Studies comparing the life history and ecology of these two common frogs are needed” (2001, 127). Predation and Defense Gray Treefrogs are masters of concealment. Prowling about at night and resting in concealment by day removes them from the attention of many predators. Moreover, during the daytime, their protective coloration, which can be changed as they change perching sites, further protects them from would-be predators. C. H. Pope (1944, 103) stated that “the moist, slightly sticky skin and toe disks enable it to perform astonishing acrobatics such as saving itself from a fall by catching a branch with one leg or landing safely on a vertical pane of glass. The long legs often propel it such distances through space that it appears to fly. As it leaps, the yellow ‘flash colors’ of the groin and legs come suddenly to view and presumably serve to confuse an enemy.” Nevertheless, Gray Treefrogs are eaten by snakes, birds, and small mammals, and the larvae are probably eaten by fishes. Harding (1997, 136) reported that “they are most vulnerable at or near breeding ponds in spring. Giant water bugs have been seen attacking these frogs in the water. Green Frogs and Bullfrogs sometimes locate and eat breeding male treefrogs by orienting to their calls.” Interaction with Humans Most people in Michigan are happy to have Gray Treefrogs around their houses and on their property and cheerfully remark about watching them on the screens of their porches or on windowpanes. Many people also know the voice of this species. Unfortunately, elimination of aquatic habitats will quickly eliminate local populations, and pesticides applied to trees and lawns will probably affect local populations adversely. Clearing of woods and removal of breeding habitats will also negatively affect the presence and overall health of the species. Behavioral Characteristics For the behavioral chacteristics of Gray Treefrogs, see the sections “Reproduction and Growth” and “Predation and Defense” in this account.

Population Health Gray Treefrogs are not listed as rare in Michigan. Judging from the widespread occurrence of both species of Gray Treefrogs in the state, the population health of these animals must be considered as stable. Declines have been noted in areas where woodlots and and vernal-pool breeding habitats have been removed. General Remarks Gray Treefrogs are the most edificarian (living in or on human buildings) amphibian or reptile species in the state. Thus, those Michiganians who migrate to Florida every winter and find it nice to have treefrogs and lizards climbing about their warm, southern “edifices” have something to be nostalgic about when Gray Treefrogs show up back home in Michigan.

Pseudacris crucifer crucifer (Wied-Neuwied 1838) Northern Spring Peeper Identification This attractive little frog, Pseudacris crucifer crucifer, the true harbinger of spring in Michigan, is only about 20 to 37 mm (.79–1.46 in.) long. It has a tan to reddishbrown coloration and usually a distinct X-shaped dark marking (hence the specific name) on its back. If this marking is indistinct, it is usually because the X pattern is somewhat broken up. The frog usually has a V-shaped line between the eyes as well, which sometimes may be indistinct or somewhat broken up. The toe tips are only slightly expanded. This little frog has the ability to change color to a degree and may darken or lighten its body in response to changes in the environment. The species has a very characteristic sharp peep during the early spring breeding season. A chorus of Northern Spring Peepers sounds to me like a bunch of peeping chicks in a hatchery. The larva is greenish brown and stippled with gold above, and the belly is an iridescent bronze. The muscular part of the tail has dark spots, and the fins are high, translucent, and pigmented black, sometimes suffused with red, on the edges and tip. Two full rows of teeth occur on the upper and lower lips, with an additional very short row of teeth occurring on the lower lip. The anal opening is on the right side of the body.

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General Distribution The species as a whole occurs across the eastern United States and Canada from the Gaspé Peninsula and southern part of Quebec in the north, west to eastern Manitoba, south through eastern Texas, and east to Georgia and northern Florida (Minton 2001). Michigan Distribution The Northern Spring Peeper occurs in every county in Michigan and on Isle Royale and Drummond and Bois Blanc Islands. In the Lake Michigan Archipelago it occurs on Beaver, Garden, Gull, North Fox, North and South Manitou, and Trout Islands.

FIG. 58. Northern Spring Peeper (Pseudacris crucifer crucifer) from Ingham County, Michigan. Photograph by James H. Harding.

Geographic Variation As far as I am aware, no distinct populations of Pseudacris crucifer crucifer exist in Michigan. Another subspecies of P. crucifer occurs in southern Georgia and northern Florida, namely P. c. bartramiana (Harper 1939), the Southern Spring Peeper. Habitat and Habits In Michigan, Spring Peepers occur mainly in the various types of woodlands that exist in the state, but they can also be found in disturbed habitats, such as old fields and brushy areas. They are not averse to utilizing isolated woodlots as habitat. Spring Peepers will breed in both temporary and permanent shallow water situations, but they prefer that such ponds are under the cover of trees. Like the Gray Treefrog, Spring Peepers can survive

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subfreezing temperatures, which probably is one of the reasons the species ranges far to the north in North America. With reference to the Chicago area, C. H. Pope (1944, 97) stated that “this species, one of the hardiest frogs, emerges from hibernation when the air temperature first exceeds 40ºF. The earliest choruses are heard when warm weather sends the mercury to 52ºF. or higher but an individual caught in the descending temperature of a cold snap has been known to sing until the mercury dropped to 30ºF.” I have heard Northern Spring Peepers singing during snowfalls in both Indianapolis, Indiana, and the Lansing area in Michigan several times. Ruthven et al. (1928, 44) stated that “during the summer it [P. crucifer] may be found among fallen leaves and moss in damp places, where the color helps to conceal it. It may frequently be found in gardens and in orchards, searching for small insects and worms.” Minton (2001, 122–23) stated that “swamps and moist woods with shallow ponds are optimal habitat for Spring Peepers. They favor upland and tend to avoid floodplain forest. In former prairie regions, they are local and uncommon and usually disappear from intensively cultivated areas.” Referring to the Chicago area, C. H. Pope (1944) commented that soon after the tadpoles metamorphose to the adult form, they spread out over the landscape, where they look for moist, shady areas with dead leaves or low vegetation. He also pointed out that eventually some individuals wander into orchards and other relatively dry open areas, where they climb into bushes and sometimes even low trees. Reproduction and Growth In Michigan, Northern Spring Peepers usually begin calling from breeding ponds in April in the northern part of the state and in late March or early April in the southern part. My own observations are that temperature, humidity, rainfall, and wind velocity appear to be important factors in starting and maintaining these choruses. I have seen calling males at the water’s edge with only their heads showing and others calling from shrubs, mounds, or clumps of grass with their whole body exposed. Some male Spring Peepers, referred to as satellite males, remain silent and station themselves near a calling male in an attempt to intercept females attracted to the vocal one. In the late summer and fall, male P. crucifer may occasionally call well away from breeding

2. Species Accounts

sites. Carpenter and Delzell (1951) suggested that Northern Spring Peepers in Michigan hibernate some distance from their breeding sites and migrate back to them when the weather improves. This might explain why the call of the Spring Peeper, in some cases, may be heard a day or two later than the Chorus Frog in some localities. Harding (1997) noted that females may prefer males that have louder and more rapid calls. These males are usually the older and larger. Amplexus soon follows the contact between the female and her chosen male. The eggs, which range in number from about 700 to 1,300, are laid one at a time or in small clusters. These are usually placed in irregular rows and attached to such objects as twigs or aquatic plants. The larvae hatch in approximately four to fifteen days and then transform into frogs about forty to ninety days later. These tiny animals are about 13 mm (.51 in.) long. Most Northern Spring Peepers are able to breed the spring after their metamorphosis, at a length of about 20 mm (.79 in.). In Indiana, Minton (2001, 123) reported that “a large chorus [of Spring Peepers] at close range is almost deafening. At Indianapolis choruses begin about the first week in March if there have been one or more mild rainy nights. The season is about two weeks later in northern Indiana. I have heard sporadic calls during the winter in the Ohio valley.” C. H. Pope (1944, 96) described mating in Pseudacris c. crucifer in the Chicago area: “Upon finding a mate, the male mounts her and takes a tight grip with his arms so that his hands sink in her armpits. The female, clinging to some submerged stem or leaf with her fore limbs, soon turns her cloaca upward, as an egg (rarely two) appears at its orifice. The male now lowers his rear end, which, upon meeting hers, emits spermatozoa. The female next bends her body downward and away from her mate, sticking the egg to a supporting object.” Diet Harding and Holman (1992) have reported that in Michigan Northern Spring Peepers feed on small invertebrates, such as insects, spiders, and mites, and that the little frogs will climb into bushes and other vegetation to hunt their prey. C. H. Pope (1944) reported that in the Chicago area Spring Peepers feed on various insects and their aquatic larvae and that abundant

remains of spiders have been found in the stomachs of the adults. In a comprehensive study, Oplinger (1967) found that ants, beetles, and spiders were the most often eaten prey of the Spring Peeper and that caterpillars of small size, mites, snails, springtails, and ticks were also part of the regular diet of the species. Predation and Defense Not a great deal on the subject of Spring Peeper predation and defense has been published. Harding (1997) has pointed out that in the Great Lakes region, Northern Spring Peeper larvae are eaten by water bugs, diving beetles, spiders, and dragonfly nymphs. Fishes, larger frogs, snakes, and many bird species eat the adults. C. H. Pope (1944) reported that a colleague had witnessed the capture of a mature larva by a large spider and that this invertebrate dived and seized its victim and then dragged it out of the water. The fact that Spring Peepers are protectively colored and breed in relatively cold, often temporary ponds reduces their contact with many potential predators. Interaction with Humans Especially in the northern areas of the Midwest, people long to hear the first choruses of this tiny frog as an announcement of the long-awaited coming of spring. When I lived in central Illinois, I knew people who would drive to the southernmost part of the state during what I considered to be midwinter to hear the first choruses of Spring Peepers and a few other hylid frogs. In Florida, where Pseudacris crucifer bartramiana breeds from January 1 to March 24 (Carr 1940), herpetologists raised in the north become nostalgic for their former homes when these “winter frogs” start breeding. During the cold, cloudy winters of Michigan, people can become psychologically disturbed because they so seldom see the sun. Others I know would likely “head for the couch” if the frog harbingers of spring in Michigan decided to quit singing. Behavioral Characteristics For the behavioral characteristics of Northern Spring Peepers, see the section “Reproduction and Growth” in this account.

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The Amphibians and Reptiles of Michigan

Population Health This species is relatively common in all parts of the state and is not protected as rare in Michigan. General Remarks Plenty of baseline ecological studies can still be done on this relatively abundant and fascinating species.

Pseudacris maculata (Agassiz 1850) Boreal Chorus Frog Identification and Comments In Michigan, the Boreal Chorus Frog occurs only on Isle Royale (Harding and Holman 1992, 66; Casper 2002). As its name implies, it is a denizen of the far north. Pseudacris maculata was only recently split off as a full species from the Western Chorus Frog (Pseudacris triseriata), which occurs in the rest of Michigan and is discussed in the next account. These two Chorus Frog species are very similar to each other, except P. maculata has shorter legs and takes shorter hops than P. triseriata. Also, the three broad stripes that occur on the back of P. triseriata tend to appear as three rows of spots in P. maculata. Based on the fact that the Western Chorus Frog occurs throughout both peninsulas of Michigan, it may be that the Boreal Chorus Frog reached Isle Royale from the west (Minnesota or Ontario).

Pseudacris triseriata (Wied-Neuwied 1838) Western Chorus Frog Identification Like the two other species of Pseudacris in Michigan—Pseudacris crucifer crucifer (Northern Spring Peeper) and Pseudacris maculata (Boreal Chorus Frog)—the Western Chorus Frog is another early harbinger of spring. Pseudacris triseriata has three relatively wide gray or dark brown stripes that run down its back along with a conspicuous stripe that runs through the eye. Another distinctive mark is a cream-colored stripe on the upper lip. The overall color may be tan, gray, or occasionally rusty orange. The ends of the toes are slightly expanded as discs. The length of the adults

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ranges from about 30 to 38 mm (1.18–1.50 in.). The voice of the male of this species is a trill that can be roughly imitated by strumming the teeth of a short pocket comb with the thumbnail. The larva is dark above and finely stippled with a metallic gold-copper color below. Two rows of teeth occur on the upper lip and three on the lower lip. The labial papillae are not turned in at the corner of the mouth. The anal opening is on the right side of the body. General Distribution The Western Chorus Frog range is bounded on the north and east by southern Quebec to the central part of Wisconsin, Iowa, Kansas, and eastern Oklahoma and on the south back across the Midwest through Missouri, Ohio, and western Pennsylvania. Michigan Distribution Just a few years ago, Harding and Holman (1992, 68) stated that “chorus frogs seem to be absent from the Upper Peninsula mainland,” even though Ruthven et al. (1928) indicated there were records (although undocumented by specimens from the University of Michigan Museum of Zoology) from Dickenson and Iron counties in the western part of the UP. Since 1996, the Michigan Frog and Toad Survey group has recorded Pseudacris triseriata from every county in the Upper Peninsula except the westernmost two, Ontonagon and Gogebic counties, thus substantiating the two earlier UP county records. In the Lower Peninsula, the Western Chorus Frog likely occurs in all counties; however, it has not been recorded from Kalkaska, Crawford, and Oscoda in the northern part of the Lower Peninsula and Branch County in the southernmost tier of counties. Geographic Variation Sometimes the three broad stripes on the back of P. triseriata are broken up into rows of spots (as occurs in specimens of P. maculata), but I do not think that discrete populations with this character have been identified in Michigan. But, if short-legged, broken-striped chorus frogs are found in the western part of the UP, questions about full species rank for maculata might emerge.

2. Species Accounts

Fig. 59. Western Chorus Frog (Pseudacris triseriata) from Ingham County, Michigan. Photograph by James H. Harding.

Habitat and Habits Western Chorus Frogs occur in a variety of habitats, such as swamps, marshes, old fields, and damp woodlands. After the breeding season they seem to disappear, but they can occasionally be found under logs, boards, or flat trash objects. Relative to the Great Lakes region, Harding (1997, 129) has stated that “they tend to remain near their breeding sites year-round, spending most of their time hidden beneath logs, rocks, and leaf litter, or in loose soil or animal burrows; they hibernate in these places as well. They occasionally move about on the surface on warm, rainy nights. Chorus Frogs are poor climbers but occasionally ascend clumps of grass or other small plants, perhaps in search of food.” From time to time, I have seen Western Chorus Frogs actively jumping about on the damp floor of white pine–aspen woodlands in the late summer in Grand Traverse County, usually after soaking rains. In Indiana, Minton (2001) has also reported that P. triseriata is difficult to find after the breeding season, but that he has occasionally seen them hopping about on the woodland floor in dense forests and has found a few under rocks and litter. One lived for a year in his yard in Indianapolis and could always be located under leaves in a window well or beneath a wooden box shaded by shrubbery. In the Chicago area, C. H. Pope (1944) stated that P. triseriata frequents damp woods, where it hides under dead leaves and logs, and marshy areas.

Reproduction and Growth Both Western Chorus Frogs and Northern Spring Peepers begin calling at about the same time in Michigan, often when patches of snow are still melting on the the woodland floor and sometimes when the ice has not fully receded from the breeding ponds. Frog lovers sometimes argue or at least speculate about which species begins calling first. I think who calls first is based on the type of breeding site each typically occupies and the local conditions that occur in any given year. Spring Peepers characteristically call in ponds that occur under closed canopy situations, whereas Western Chorus Frogs characteristically call from very shallow ponds in open grassy areas. A few days of warm, rainy, windy weather will quickly melt the ice on open ponds. But ice on closed canopy ponds remains much longer in such weather. In such situations P. triseriata may call first. If in early spring, the low, open areas are subject to dry and windy conditions for an extended time, there may be few sites where P. triseriata can breed, and the Spring Peepers in their sheltered ponds may sing first. C. H. Pope (1944), to illustrate the breeding habits of the Western Chorus Frog in the Chicago area, rendered a drawing from a photograph of a male P. triseriata, with its relatively huge and expanded vocal sac, nose to nose with an interested female. They both are on matted, dead grass (192, fig. 21). Pope stated (about the figure) that “after such preliminaries, the male mounts his mate, sinking his hands in her armpits. The pair apparently lay [their eggs] while under the water, the female clinging with her forelimbs to a blade of grass or some similar object” (91). Harding (1997) reported that in the Great Lakes region during amplexus the female of P. triseriata lays from about 500 to 1,500 eggs. The eggs are in rather loose, gelatinous clusters that are attached to underwater grasses or sticks. Each of these clusters comprises about twenty to three hundred eggs. The rate of growth and development of the embryos depends on the water temperature. The larvae hatch in from three to fourteen days. The larvae transform into tiny frogs 8 to 12 mm (.31 to .47 in.) in length about forty to ninety days later. These froglets grow to breeding size in less than a year. Minton (2001) reported that in New Albany, Indiana, amplexus has been observed in the species as early as February 24 and in Indianapolis about a hundred

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The Amphibians and Reptiles of Michigan

miles farther north as early as March 5. Whitaker (1971) reported that eggs were laid by Western Chorus Frogs in Vigo County, Indiana, between March 12 and April 12. Minton (2001) found newly transformed frogs with body lengths from 9.5 to 12 mm (.37–.47 in.) on May 19 at New Albany, Indiana. Diet Harding and Holman (1992) reported that in Michigan P. triseriata feeds upon several kinds of insects, spiders, and other invertebrates, and that the larvae feed mostly on algae. Ruthven et al. (1928) reported that P. triseriata fed upon insects but included no further detail about the diet of these animals. In Indiana, Whitaker (1971) found that Chorus Frogs in Vigo County consumed species from thirty taxonomic groups and that ants, spiders, lepidopteran larvae, beetles, and small snails were the most frequently eaten prey. They also reported that smaller individual frogs ate springtails and mites and the tadpoles fed on algae. Predation and Defense Little has been written about predation and defense in the Western Chorus Frog in Michigan. In the Great Lakes region, both Gartersnakes and Ribbonsnakes are known to prey upon P. triseriata, and these frogs are clearly food for birds and small mammals (Harding 1997). The main mechanism of defense in these frogs is probably concealment, along with their habit of rarely exposing themselves except during the breeding season. Even when they are active during the breeding season, it is difficult to discern them among dead reeds and grasses. Entire choruses of breeding P. triseriata have the eerie ability to all stop calling at once when relatively distant sounds occur. I have noticed this when cars drive by their breeding sites, or even when low-flying planes pass over the area. In the Chicago area, C. H. Pope (1944, 94) pointed out that “garter and ribbon snakes no doubt devour countless numbers of swamp tree frogs; there are two definite records of one having fallen victim to Thamnophis sirtalis sirtalis, and Gloyd [Howard K. Gloyd] saw specimens of Thamnophis sauritus proximus [Orangestriped Ribbonsnake] eating them in Kansas. He also took one from the mouth of a leopard frog.” Pope went on to point out that the larvae of P. triseriata become less

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able to avoid predators as the temporary water of the breeding site dries up. Interaction with Humans In Indiana, Minton (2001, 121) attested to the defensive value of concealment in the Western Chorus Frog when he stated that “nearly every Hoosier has heard its voice, although few know it by sight. I have heard its call ascribed to birds, insects, salamanders, and larger species of frogs. In parts of southern Indiana and Kentucky, both this frog and Pseudacris crucifer are called ‘peepers,’ and it is believed that they can be seen only by persons with brown eyes.” I want to bear witness to the fact that the last part of the previous sentence is not true, as I have blue eyes and have seen both of the species. Even though the art of concealment in Western Chorus Frogs tends to protect them from the grabbing hands of humans of various ages, many of the shallowwater sites used by this species can be affected by surface runoff that may contain pesticides, herbicides, and other pollutants that may kill both eggs and larvae. Obviously the joy factor that accompanies these seen or unseen but always heard little frogs is an important interaction for humans. Behavioral Characteristics For the behavioral characteristics of the Western Chorus Frog, see the sections “Reproduction and Growth” and “Predation and Defense” in this account. Population Health The Western Chorus Frog is not protected in Michigan. Although it is widespread in the state, declines have been noticed in some portions of Michigan. Relative to this species’ presence in the Great Lakes area, Harding (1997, 130) stated that “local declines in Chorus Frog numbers have been reported but remain poorly studied; natural factors affecting populations (such as climatic variations) must be separated from those caused by humans.” General Remarks As researchers have indicated, many baseline ecological studies still need to be done on this species in Michigan. Also the relationships between Pseudacris maculata on Isle Royale and Pseudacris triseriata in the rest of Michigan need to be explored.

2. Species Accounts

Family Ranidae As in the frog family Hylidae, the Ranidae contains a large number of genera and species. The Ranidae is cosmopolitan except for southern South America and most of Australia (Frost 1985). Forty-six genera and about 625 species were recognized in 1992 (Duellman 1993). Ranid frogs are variable in size, structure, and ecological roles. Many small species are under 50 mm (1.97 in.) in snout-to-vent length, many others are of moderate to large size as frogs go, and one giant species, Conraua goliath, which is the largest known living frog, reaches a snout-to-vent length of 300 mm (11.81 in.) (Duellman and Trueb 1986). Only the genus Rana of this family occurs in North America. General characteristics of Rana species in North America include paired vocal sacs, one on each side of the throat; a generally smooth skin; a narrow waist; free fingers and webbed toes; and a generally large tympanum (a round, thin-skinned, external ear drum). Six species occur in Michigan: three are aquatic green frogs (American Bullfrog, Northern Green Frog, and Mink Frog); two are leopard frogs (Northern Leopard Frog and Pickerel Frog); and one is a brown frog (Wood Frog). The green frogs are the largest and most aquatic, the leopard frogs are smaller and spend more time on land, and the brown frog is the smallest and completely terrestrial except during the breeding season. Interestingly, three similar groups of Rana but with different specific names occur in northwestern Europe. Many North American ranids, including those in Michigan, were assigned to the new genus Lithobates by Frost et al. (2006), but this change remains controversial (see Pauly et al. 2009), so in this book I retain the traditional use of the genus Rana pending longer-term acceptance of the proposed change.

Rana catesbeiana Shaw 1802 American Bullfrog Identification The American Bullfrog is probably the largest frog in North America (Conant and Collins 1998). It is difficult to misidentify an American Bullfrog in the field in Michigan. Dorsolateral folds (conspicuous ridges of skin that start above the tympanum and run along both sides of the back) are

absent. Nevertheless, a ridge begins at each eye and curves behind the tympanum to the shoulder area. The overall color may be green, yellowish green, brown, or olive. The back and upper portions of the legs occasionally have dark marks. The belly is white or cream-colored and may be mottled with gray. The toes of the hind feet have webs extending to their tips except for the longest toe (toe 4), which is not fully webbed. The adult body length may reach 203 mm (7.99 in.) in length (Harding 1997).

Fig. 60. American Bullfrog (Rana catesbeiana) from Jackson County, Michigan. Photograph by James H. Harding.

The larva is brownish green and spotted or marbled with darker colors above. Its belly is a yellow color. The tail crest is not extended on the back. The upper part of the crest is finely spotted with black and the lower crest is usually immaculate. The upper lip has two rows of teeth and the lower one has three. The lower lip and the sides of the upper lip are bordered with papillae, which are folded in at the corners of the mouth. The anal opening is on the right side of the body. General Distribution The original range of the American Bullfrog was from Nova Scotia west to Wisconsin and then locally to eastern Wyoming and eastern Colorado, and south into Tamaulipas and Coahuila, Mexico (Minton 2001). But the Bullfrog has been introduced widely across the world in such places as the far western United States; southwestern British Columbia, Canada; localities in Europe such as Spain, France, the Netherlands, and

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The Amphibians and Reptiles of Michigan

southern England (see Arnold and Ovenden 2002); islands in the West Indies; and Taiwan. Michigan Distribution The American Bullfrog has been recorded in Michigan from every county in the Upper Peninsula as well as Bois Blanc Island, and Beaver and North Manitou Islands in the Lake Michigan Archipelago. It can also be found along the shores of islands situated in the Detroit River and Lake Erie. Harding and Holman (1992) indicated by map that this species is found on Drummond Island, but I cannot find any records in the literature to back that up. In the Lower Peninsula, records are absent in several counties, including Gladwin, Missaukee, Roscommon, Benzie, Crawford, Oscoda, Alpena, Presque Isle, and Emmet in the upper part of the Lower Peninsula. I can see no pattern in this lack of county records and cannot offer any explanation for this other than possible lack of anuran surveys at the time this species calls. There is no reason American Bullfrogs should not occur in all these counties, and thus it is likely they are present but not documented. Geographic Variation As far as I can determine, there is no evidence of geographic variation in populations of Rana catesbeiana in Michigan. Habitat and Habits In Michigan, American Bullfrogs inhabit permanent aquatic situations, such as natural ponds, farm ponds, lakes, sloughs, various impoundments, and shallow bays of the Great Lakes. Sometimes large numbers of juvenile or even adult American Bullfrogs can be observed on exposed mudflats in the bends of relatively swift streams and rivers in the state. Bullfrogs are most common in warmer waters with large amounts of aquatic vegetation. Both the tadpoles and adults burrow into the mud at the bottom of their aquatic habitats for winter hibernation. In the Great Lakes region, this hibernation may last from about mid-October until April or May. Adult frogs often cease activity earlier in the fall and come out of hibernation later in the spring than tadpoles or young frogs (Harding 1997). About American Bullfrogs in Michigan, Ruthven et al. (1928, 53) stated that “it is strictly aquatic. It

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is found during the summer in large ponds or lakes, usually those with mud bottoms, and with deep as well as shallow water. It is a powerful swimmer, due to the fact that the hind limbs are long and well-developed and the toes are fully webbed.” Minton (2001, 132) reported that in Indiana “permanent water is essential for this frog, since two years may be spent in the tadpole stage. The water must be quiet, shallow in places, and must warm up to about 70ºF at least near the surface. Typical habitats include lakes, stock and strip mine ponds, permanent marshes, and sloughs and backwaters of larger streams. They tolerate polluted and very muddy water better than most frogs and may be found in sluggish streams and ponds within large cities.” Relative to the Chicago area, C. H. Pope (1944) pointed out that typical habitats are small lakes and permanent ponds with aquatic plants and “rubbishchoked” shallows next to banks with willows and other kinds of low trees. He mentioned that any permanent, quiet, shallow water with an abundant cover consisting of pickerelweed, arrowhead, water lilies, and brush or “rubbish” may be inhabited by American Bullfrogs. Reproduction and Growth In Michigan and the Great Lakes region, American Bullfrog breeding activity usually begins some time after the middle of May and peaks sometime in June. In northern Michigan, it often continues into July. Males are most active in calling on warm nights but occasionally in the daytime as well. Males call either when they are partly submerged or when they are sitting on lily pads or other objects, such as partially emergent logs. Large males defend territories that are somewhat circular and about 2 to 5 m (6.6–16.4 ft.) in diameter. The largest males take residence in the best breeding sites (Harding 1997). A male within his territory makes a one- or two-note call to warn other approaching males. If this warning is ignored, what has been called a “wrestling match” ensues, after which the defending male usually drives off the intruder. Female American Bullfrogs appear to select a mate relative to the suitability of his territory as an egglaying site. But sometimes pairs will move away from the male’s territory and select another territory for breeding purposes. The female deposits from about five thousand to more than twenty thousand eggs during amplexus. They form a floating mass that can be up to

2. Species Accounts

a meter (3.28 ft.) in diameter. The individual eggs are tiny and hatch in about three to six days. Some tadpoles are able to metamorphose into small frogs during the next summer, but many do not metamorphose until the third summer. Small American Bullfrogs normally reach breeding size in three or four years, when they are about 100 mm (3.9 in.) long. Ruthven et al. (1928, 53) reported that in Michigan “the song is a deep bass note that resembles the roaring of a bull, hence the common name, bullfrog. It is late in coming from hibernation; the eggs are laid in May or early June. Metamorphosis is delayed until the second year and sometimes the third if the environment is unfavorable.” Minton (2001, 133) characterized the call of Bullfrogs in Indiana a little differently; he stated that “the characteristic mating call of the male Bullfrog resembles the syllables ‘brr-wum’ in a very deep, bass, reverberating voice and repeated at intervals of several minutes.” I have sometimes described the American Bullfrog call in Michigan to students as a very deep, flat “boo-ruh-muh” or sometimes a protracted “boo-ruhmuh muh.” Diet Adult American Bullfrogs literally eat any live animals that they can swallow. Amphibian books often contain photographs of Bullfrogs eating live snakes and even birds (see Harding and Holman 1992, 110). When American Bullfrogs have large prey in their mouth, they use their hands to keep stuffing the animal in, and they simultaneously depress their large, muscular eyeballs to move the item on down into their throat. In Michigan, Harding and Holman (1992) report that American Bullfrogs eat insects, crayfish, smaller frogs, fishes, small snakes and turtles, mice, and birds. In Indiana, Minton (2001) looked at the stomachs of seven adult American Bullfrogs and found that crayfish, tadpoles, and large insects such as diving beetles and water bugs made up the bulk of the food. He also found Cricket Frogs in one stomach and a small mammal in another. Minton also stated that much of the American Bullfrog’s food is evidently captured below the surface of the water. But, in general, Bullfrogs often sit and wait for their prey, changing positions from time to time. Bullfrogs also locate and eat smaller frogs by orienting to their breeding calls (Harding 1997).

Predation and Defense American Bullfrogs have numerous predators, especially those that eat the tadpoles and small adults of the species. These predators include fishes such as largemouth bass, snapping turtles, watersnakes, gartersnakes, and various wading birds. Harding and Holman (1992, 85) mention a possible defensive mechanism in the American Bullfrog as follows: “A bullfrog that is frightened will often give a single ‘yelp’ as it leaps into the water. If grabbed by a predator (or human), these frogs can give a loud, wailing scream. This may startle an attacker long enough to allow the frog to escape.” The suggestion has been made that the yelp may alert other Bullfrogs in the vicinity to the presence of predators. Interaction with Humans American Bullfrogs are gathered for food by humans not only in North America but wherever they have been introduced, all over the world. Bullfrog hunting for food in Michigan does not appear to be as common as it used to be. This is partly because of the elimination of commercial harvest of this species and partly that known Bullfrog hot spots have been overly exploited. From time to time I have seen populations of Bullfrogs peak and then abruptly disappear. This is probably caused by the type of intensive night frog hunting that I have observed from time to time during field work. Hunters wearing headlamps to “shine” frogs characteristically come to the ponds in groups of three or four, each person with a gig or a short-line pole, and each carrying a bag for the frogs. When I run into such groups I get an unpleasant adrenal flush, just as I have had when stumbling onto a still or people illegally skinning alligators, and I promptly leave the area. Bullfrogs are very easy to catch out in a night or two of such hunting. Michigan law now regulates the harvest of frogs, and there is a closed season as well as bag limits for these animals. Other direct threats include habitat loss around lakes and ponds. Often where small cottages once stood there are large year-round houses, and these properties tend to have clean, vegetation-free shorelines where herbicides are also often dumped into the lake to suppress aquatic plants. Behavioral Characteristics See the sections “Habitat and Habits,” “Reproduction and Growth,” and “Predation and Defense” in this

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account for the behavioral characteristics of Rana catesbeiana. On the E. S. George Reserve near Ann Arbor, Michigan, in a now classic study, Emlen (1968) found that adult male American Bullfrogs establish definite territories from which other bullfrog males are aggressively excluded. Such areas are defended by stereotyped postures, approaches, and physical encounters. He proposed that these frogs had a polygamous social system and that this created intense competition for females by males. Moreover, he suggested that the possession of a territory directly enhances an individual male’s chances of successful mating. Population Health The American Bullfrog is not protected as threatened or endangered in Michigan. Bullfrogs are such large and aggressive species and so well adapted to their warm, sluggish, and sometimes even polluted habitats, I am surprised to read that populations are down in some areas of the state. Aquatic habitat loss along lake and pond shorelines as well as the sometimes massive amounts of aquatic weed killer applied in lakes certainly affect populations of this species. Other declines can result from overzealous Bullfrog hunting.

Rana clamitans melanota Rafinesque 1820 Northern Green Frog Identification Large specimens of Northern Green Frog are frequently confused with American Bullfrogs but are easy to distinguish from this species on the basis of the presence of a dorsolateral fold that begins at the back of the eye, passes over the tympanum, and runs at least partway down the back. The American Bullfrog has a fold that begins at the eye but immediately hooks down around the tympanum and ends. The background color of the Northern Green Frog can be green, yellowish green, olive, or brown (in Michigan, some aberrant populations are even blue). The upper lip area is green or yellow. Many individuals have dark spots on the back and sides as well as dark crossbands on the hindlegs. The belly is white and sometimes mottled with gray marks. The length of adults runs from about 60 to 108 mm (2.36–4.25 in.) (Harding 1997).

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The call of the Northern Green Frog is very characteristic and sounds to everyone like a loose string of a banjo being twanged. It is also like a “gung” sound that can be made by engaging the top of the tongue with the ulvula while saying “gung” forcefully. Others have called it a “clung” sound, but I do not agree with them at all. When I collected herps in southern Indiana years ago, I heard Rana clamitans melanota referred to as a banjer frog (banjo frog). The call may be given singly or rapidly, several times in a row—gung-gung-gung-gung-gunggung-gung—with the last few “gungs” trailing off. These are fine sounds to hear coming from lily pads on a warm June morning. The larva is brownish green above with dark spots. The belly is a dark cream color. The muscular portion of the tail is colored like the body, but the tail crests are conspicuously mottled with brown. There are two rows of teeth on the upper lip and three on the lower. The lower lip and the sides of the upper lip are bordered with papillae that are folded in at the corners of the mouth. The anal opening is on the right side of the body. General Distribution The distribution of the Northern Green Frog occurs from coastal Newfoundland and southern Quebec, Canada, to southwestern Ontario, Canada, and south to Eastern Oklahoma, southern Illinois, northern Georgia, and most of North Carolina. The subspecies R. c. clamitans occurs in eastern North America south of this range (see Conant and Collins 1998, 560, map). Michigan Distribution The Northern Green Frog has been recorded from every county in Michigan. It occurs on Isle Royale and Drummond and Bois Blanc Islands as well as Beaver, Garden, High, and North Manitou Islands in the Lake Michigan Archipelago. They can also be found along the shores and in interior ponds of the Detroit River and Lake Michigan islands. It also occurs on the Charity Islands in Lake Huron, where two specimens were found under rocks on the beach (Thompson and Thompson 1912). Geographic Variation I am unaware of any geographic variations in this animal in Michigan that would have any taxonomic or ecological significance, with the possible exception that populations

2. Species Accounts

Fig. 61. Northern Green Frog (Rana clamitans melanota) from Grand Traverse County, Michigan. Photograph by James H. Harding.

of blue-colored individuals are found from time to time (see Holman and Harding 1992, 81, illustration). I have been observing frogs in and near a lake in northwestern Lower Michigan for more than twenty years, and I have seen blue-tinted Green Frogs from time to time, but this color aberration has never swept through the whole population, as far as I can tell. Habitat and Habits Northern Green Frogs in Michigan are found in or near most inland aquatic situations, including lakes, ponds, marshes, swamps, stream banks, river banks, and soggy areas in river floodplains, and they seem to be the first frogs to invade newly constructed ponds anywhere in the state. Adult Northern Green Frogs stay near the water, but juveniles are likely to wander about during rainy weather. Harding (1997) stated that in the Great Lakes region, Green Frogs appear to be more tolerant of open aquatic sites than the American Bullfrog but that temporary water is generally avoided by adult Green Frogs. Werner and McPeek (1994) found that Northern Green Frogs in southwestern Michigan were most successful in ponds where the American Bullfrog was absent, whereas Bullfrogs were most abundant in ponds containing fishes. They found that bluegills negatively affected the invertebrate and salamander predators on both the Northern Green Frogs and the American Bullfrog larvae. Northern Green Frogs spend the late fall and winter (from about November to early April) buried in mud under the water. In rapid creeks and spring-fed ponds

that do not freeze over, Rana clamitans melanota may be active from time to time, even in the middle of winter. Ruthven et al. (1928) reported that the Northern Green Frog is thoroughly aquatic and found in most of the small streams, ponds, and cold springs in the state, but that it is much more solitary in such habitats than are Rana pipiens and Rana palustris (Leopard Frogs and Pickerel Frogs). Rana clamitans melanota also occurs throughout Indiana. Minton (2001, 129) stated that “relatively cool, clear, permanent bodies of water are favorable for this frog; warm, muddy, transient waters are avoided. Swamps, ponds, lake margins, and streams are inhabited in northern Indiana; springs, quarry ponds, and pools of woodland brooks are common habitats in the southern part of the state.” Minton also explained that Green Frogs usually do not travel more than a few feet from the water except on rainy nights. They are occasionally found in caves in Indiana. Relative to the Chicago area, C. H. Pope (1944, 126) stated that “the bullfrog and the green frog are similar in habitat preference except that the latter requires much less cover and is therefore found in almost every permanent, plant-grown aquatic situation. Ponds, lake borders, swamps, river backwaters, and streams meandering through meadows or open woodlands are the favorite haunts.” Reproduction and Growth In Michigan, male Northern Green Frogs usually start calling in May and may continue to call sporadically as late as August. The males may call while they are partially

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The Amphibians and Reptiles of Michigan

submerged or when perched on logs, lily pads, or other such structures. I have never seen them calling from wideopen areas such as extensive mudflats. Stanley (1998) studied environmental variables that might influence calling rates in a population of Northern Green Frogs at a single locality in Marquette in the Upper Peninsula. The conditions monitored for their possible effects on the number of advertisement calls given by male Green Frogs were relative humidity, barometric pressure, wind speed, cloud cover, and air and water temperature. Sampling took place between July 15 and 29. The most important factors were found to be cloud cover, relative humidity, and wind speed. The area around the site where a Rana clamitans melanota individual is calling is defended against other males of the species. When an intruder is detected, the normal single-note “gung” (the advertisement call) is replaced by “gung-gung-gung-gung-gung-gung gung.” If the intruder advances, a single, sharp squawk is sounded. If the unwanted male still continues to advance, a wrestling match may follow, accompanied by what observers have called growl-like sounds. Female Northern Green Frogs appear to choose mates on the basis of whether her potential mate is calling from a desirable place for eggs to be laid. Harding (1997, 46) described the mating and egg laying of this species in the Great Lakes region: “She approaches and turns her back toward the chosen male; he will initiate amplexus when contacted by the female. Egg laying normally occurs at night, often during rainy weather. The thin, floating egg mass is usually attached to emergent or surface vegetation and contains from 1,000 to 5,000 eggs.” In Michigan, eggs hatch about three to five days later. Larvae that emerge rather early from the eggs may transform into frogs late in the summer; larvae that hatch later in the year will not transform until the next summer. Harding (1997) stated that the newly metamorphosed little frogs average about 30 mm (1.18 in.) in length and can double in size the first year, attaining maturity the following summer. In southern Michigan it takes about four or five years for Northern Green Frogs to reach maximum size (Martof 1956). Diet In Michigan, Harding and Holman (1992) reported that the Northern Green Frog eats mainly insects and

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other invertebrates but that large adults will eat smaller frogs, including the young of their own species. Harding (1997) reported that Rana clamitans melanota in the Great Lakes region eats a variety of aquatic and terrestrial insects, such as beetles, flies, butterflies, caterpillars, grasshoppers, spiders, millipedes, slugs, snails, and crayfish. Large Green Frogs will eat smaller frogs, snakes, and even hatchling turtles. The larvae eat algae, diatoms, and other planktonic organisms. They also ingest decaying animal tissue and plant debris. Adult Rana clamitans melanota normally use the sit-andwait technique to catch prey, taking about any animal that can be swallowed. Like the American Bullfrog, they use their front legs to stuff large prey into their mouth and depress their large eyes to help push the prey down into their throat. Green Frogs key in on movements of their prey as well as the calls of smaller frogs that might be potential prey. Predation and Defense In Michigan small Green Frogs are undoubtedly eaten by the adult versions of the prey that large Green Frogs feed upon, such as Gartersnakes (Thamnophis sirtalis), Watersnakes (Nerodia sipedon), and a variety of aquatic turtles. Fishes eat the larvae, and a variety of wading birds, especially herons, use the stand-and-wait policy to catch these frogs. Referring to the Great Lakes region, Harding (1997) has pointed out that the eggs of Northern Green Frogs are eaten by leeches, aquatic insects, and Painted Turtles (Chrysemys picta); the larvae are eaten by predaceous insects as well as fishes, turtles, and herons. After metamorphosis, Green Frogs are consumed by larger frogs, turtles, snakes, wading birds, raccoons, otters, mink, and occasionally humans. Unlike many other anurans, Green Frogs seem to lack noxious skin secretions that discourage potential predators. In its favor, this species is not only alert but very agile. Also, it has eyes that are able to detect the slightest motion, which not only alerts them that prey is near but that predators may be nearby as well. When predators are detected, Green Frogs normally leap into the water, often giving a loud cry. When they land in the water, they bury themselves in the mud on the bottom or crawl under submerged vegetation or other such objects. Other Green Frogs are also probably alerted that predators are on the loose by this behavior. I have

2. Species Accounts

observed Northern Green Frogs that have been seized by the leg by Common Watersnakes (Nerodia sipedon sipedon) in both Michigan and Indiana. The adult Indiana frog gave an elongated, piercing squawk when seized, but the two small Michigan Green Frogs did not emit a cry, or at least not one that I could hear.

determination. Because Northern Green Frogs and Mink Frogs already have important characters in common, such as size, extent of toe webbing, degree and development of dorsolateral folds, and color patterns of the hind legs, further comparative analyses of both of these frogs are needed in the Upper Peninsula.

Interaction with Humans Green Frogs are captured and eaten by humans in both Michigan and the entire Great Lakes region. Because of their smaller size, Green Frogs are not as much sought after as the American Bullfrog. The state of Michigan regulates the harvesting of Green Frogs by means of a bag limit and a closed season.

Rana palustris LeConte 1825 Pickerel Frog

Behavioral Characteristics For the behavioral characteristics of the Northern Green Frog, see the sections “Habitat and Habits,” “Reproduction and Growth,” and “Predation and Defense” in this account. Population Health The Northern Green Frog is the most abundant Rana species in Michigan and is not protected as rare by the state. Some herpetologists suggest that Northern Green Frogs may be filling in niches left open by declining populations of Northern Leopard Frogs. In recent years Green Frogs have been observed occupying habitat niches previously not used by this species. They tend to avoid seasonal vernal pools; however, studies in urban areas are showing that this species is moving into such habitats. This shift has resulted in displacement of smaller species or reduction in their overall numbers because of increased predation pressure by Green Frogs. General Remarks Costabile et al. (1993) reported a possible hybrid individual between the Northern Green Frog (Rana clamitans melanota) and the Mink Frog (Rana septentrionalis) in the Upper Peninsula of Michigan. The Green Frog is common all over Michigan, whereas the Mink Frog occurs only in the Upper Peninsula. Adults of both species and the hybrid were cleared and stained, and bony and cartilaginous elements of the skull were compared. External characters of these frogs were analyzed along with habitat and behavioral factors to make this

Identification Pickerel Frogs are sometimes confused with the Northern Leopard Frog in Michigan and the Great Lakes region, but the following characters in combination should allow ready identification of Rana palustris. The general color is brown or green marked with two rather irregular rows of squarish dark spots extending down the back and other spots on the sides and legs. A light line occurs on the upper jaw, and the dorsolateral folds are light-colored as well. The belly is whitish. A very important character of this species is that the groin and bottom of the legs are bright yellow or orange. In Michigan the adult length is about 44 to 87 mm (1.73–3.43 in.). The advertisement call of the male Pickerel Frog is similar to that of the Leopard Frog, except that it is shorter and softer and does not carry as well. C. H. Pope (1944, 130) described the voice of this species: “The call, low in pitch and with little volume, sounds like a ‘gentle, musical snore,’ and lasts but half a second. It is often thought to be the subdued note of a leopard frog. Both of these species actually croak under water.” The larva back is brownish green with dark spots, and the belly is iridescent. The tail is dark and strongly marked with black and yellow. The upper lip has two rows of teeth and the lower one has three. The lower lip and the sides of the upper lip are bordered with papillae. The anal opening is on the right side of the body. General Distribution In Canada, the Pickerel Frog occurs in Nova Scotia, New Brunswick, and southern Ontario; the range boundary also extends west to Wisconsin and south to eastern Texas, southern Alabama, and South Carolina. Pickerel Frogs are absent, however, from many areas within this range (Minton 2001).

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Michigan Distribution The Pickerel Frog has been recorded from all the counties in the Upper Peninsula, but I am unaware of any records from Michigan islands. Harding and Holman (1992) incorrectly indicated on a map that this species occurred on Drummond and Bois Blanc Islands as well as five islands in the Lake Michigan Archipelago (see Bowen and Gillingham 2004). This species is widespread but generally uncommon to rare in the Lower Peninsula of the Michigan. It has not been reported from several counties in the Lower Peninsula, but there is really no pattern to this lack of records. Habitat and Habits Compared to other Rana species in Michigan, the Pickerel Frog is very sensitive to polluted water and quickly disappears from such situations. It can be common, though, where its preferred habitats are rather pristine. These situations are the grassy or marshy edges of unpolluted lakes, bogs, streams, and springs. They prefer colder water than the closely related Northern Leopard Frog and are much less likely to move long distances away from aquatic areas. Ruthven et al. (1928, 57) stated that “the pickerel-frog resembles Rana pipiens very closely in appearance and habits. It lives along streams, ditches, about lakes, ponds and cold springs, and seems to prefer water of a rather low temperature.” The habitat of this frog in Indiana is also very restricted but somewhat different from that in Michigan

FIG. 62. Pickerel Frog (Rana palustris) from Barry County, Michigan. Photograph by James H. Harding.

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because of the different habitats available there. Minton (2001, 145–46) stated that “Indiana Pickerel Frogs are nearly always found near cool, spring-fed streams and, in southern Indiana, often in or near caves. They are rarely found far from water but often try to escape by leaping into undergrowth. In southern Indiana, the young are often found under stones in creeks.” C. H. Pope (1944) reported that in the Chicago area the Pickerel Frog inhabits all aquatic situations that combine clear, cool water with tall grass and other kinds of low vegetation; the most typical habitat consists of clear, spring-fed streams that flow through wet meadows with an abundance of thick grass. Reproduction and Growth In Michigan the Pickerel Frog breeds in April or early May. Mating starts with the males calling while either floating on the surface or being submerged. During the process of amplexus, which may last for several days, a single female is able to deposit from about eight hundred to three thousand eggs in one or more rounded clusters. These clusters are attached to submerged material such as grasses and twigs. The tadpoles hatch in about ten to twenty days, depending on the temperature (higher temperatures shorten the length of the incubation period). Metamorphosis takes from about one to three months, again depending on the temperature of the season. The new frogs are about 20 to 30 mm (.79–1.18 in.) long, and they become ready to mate the next spring. Ruthven et al. (1928, 58–59) commented that “the breeding season in southern Michigan is in April and May, rather later than that of Rana pipiens. Our earliest Ann Arbor record for the species is April 10. The eggs are small; they are laid in irregular masses about two inches in diameter, attached to sticks. The young tadpoles leave the eggs usually within a week; transformation occurs in late July or in August. The young frogs are very distinctive in appearance, the rectangular spots standing out in sharp contrast to the bronze of the back.” In Indiana, relatively little information is available about the reproduction and growth of the Pickerel Frog. Brown (1984) reported on finding a Pickerel Frog laying eggs in a pool about 50 m (164 ft.) from the entrance of a cave in Spring Mill State Park in southern Indiana on March 10. The air temperature at the time was 14ºC (57.2ºF).

2. Species Accounts

Diet In Michigan, Pickerel Frogs are reported to eat a variety of insects, spiders, snails, worms, and other invertebrates. In the Great Lakes region, Harding (1997) reported that Pickerel Frogs will eat either terrestrial or aquatic prey and that their larvae are largely herbivorous, eating algae and soft plant material but consuming dead animal material on the bottom as well. Ruthven et al. (1928) reported that the food of Michigan Pickerel Frogs is small crustaceans, snails, and insects. In Indiana, Minton (2001) stated that Pickerel Frogs are reported to eat a variety of predominantly terrestrial insects and other invertebrates. Predation and Defense Not a great deal of reliable information is available about which animals are the principal predators of Pickerel Frogs. In fact, most of the literature concerns reports about the noxious secretions that these animals possess and how they affect potential predators. But C. H. Pope (1944) reported that Bullfrogs and Green Frogs “relish” small Pickerel Frogs, and that Newts eat their eggs. Pope also stated that “collectors soon learn to isolate their catch because the poisonous secretion of the skin quickly kills other amphibians confined with pickerel frogs” (131). Animals alleged to leave Pickerel Frogs alone, presumably because of their poisonous nature, are Gartersnakes, Ribbonsnakes, and Watersnakes. Harding (1997) reported that mink are known to eat Pickerel Frogs but that accounts in the literature describing the reaction of predators to Pickerel Frogs are mainly anecdotal and may be conflicting. Ruthven et al. (1928, 57–58) pointed out characteristics of this species that obviously help Rana palustris avoid predators when they stated that “its coloration is extremely protective; when resting on dried leaves or sunlit grass the animal can scarcely be seen. It is much more difficult to capture than the leopard-frog, for its leap is long and swift and it takes to the water very quickly when alarmed.” Interaction with Humans Anyone handling Pickerel Frogs should keep these anurans away from their eyes, nose, and mouth and should immediately and thoroughly wash their hands after releasing these animals. Some people react more negatively to amphibian secretions than others, as

I relate on the pages about salamanders. Likely frogs, snakes, birds, and mammals have varying individual responses to noxious secretions just as humans do. Since Pickerel Frogs prefer cool, clear, unpolluted water, it goes without saying that these kinds of natural situations need to be preserved if they are to survive in Michigan or anywhere else. Of all the aquatic situations in the Great Lakes region, it would seem that Pickerel Frog habitats would be the most difficult to “bring back.” Behavioral Characteristics For the behavioral characteristics of Pickerel Frogs, see the sections “Habitat and Habits,” “Reproduction and Growth,” and “Predation and Defense” in this account. Population Health Although generally uncommon, Pickerel Frogs are not considered threatened or endangered but are indicated as Species of Greatest Conservation Need in Michigan. The species has been proposed for inclusion as a Species of Special Concern. It is interesting to note that Ruthven et al. back in 1928 listed “ditches” as a habitat for Rana palustris. This species is not found in “ditches” today in Michigan, and their absence probably reflects the increase in general pollution that has occurred in the state since the researchers published their accounts. General Remarks It will be very interesting to see what the status of this frog with such specific habitat requirements will be in Michigan twenty years from now. By the way, the common name of Pickerel Frog comes from the fact that it was once used for pickerel bait.

Rana pipiens Schreber 1782 Northern Leopard Frog Identification The Northern Leopard Frog is similar to the Pickerel Frog, enough so that they are both placed in the “Leopard Frog Group.” But, this species has rounded dark spots on the back and sides, whereas these spots are rectangular and arranged in two irregular rows on the Pickerel Frog. The best character for instant identification is that the Northern

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Leopard Frog lacks the conspicuous bright yellow or orange groin and bottom side of the back legs that occur on the Pickerel Frog. Additionally, the dorsolateral folds of the Leopard Frog are generally much lighter in color and more conspicuous than those of the Pickerel Frog. Adult Northern Leopard Frogs in Michigan are about 50 to 100 mm (1.97–3.94 in.) long. The call of the Northern Leopard Frog sounds very much like a person slowly strumming an inflated balloon with the thumb, trying to make a sound like a low, rumbling snore interspersed with clucks and croaks. The larva is brown and speckled with gold above and iridescent bronze below. The tail is a lighter color, and the crests show scattered dots and thin streaks of black. Both the upper and lower lips have three rows of teeth, and the sides of the upper lip are bordered with papillae. The anal opening is on the right side of the body. General Distribution Rana pipiens has a large and complex range that extends from Labrador, Quebec, and isolated populations in Newfoundland west to the Northwest Territories and southeast British Columbia in Canada; south through New England and most of Pennsylvania; and west to central Kentucky, Iowa, Colorado, Nevada, northern New Mexico, and Arizona. Isolated populations have been recorded in Oregon, California, and Washington. Michigan Distribution The Northern Leopard Frog has been recorded from every county in Michigan as well as on Beaver, Garden, and South Manitou Islands in the Lake Michigan Archipelago and Charity Island in Lake Huron. Harding and Holman (1992) incorrectly indicated on a map that Rana pipiens has been recorded on other islands in the Lake Michigan Archipelago as well as Drummond and Bois Blanc Islands (see Bowen and Gillingham 2004). Relative to Rana pipiens in Michigan, Harding and Holman (1992, 86) stated that “at one time this was the most abundant frog in the state, but populations declined drastically in the 1970s for unknown reasons.” Geographic Variation I am not aware of any significant geographic variation of this species in Michigan.

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FIG. 63. Northern Leopard Frog (Rana pipiens) from Ingham County, Michigan. Photograph by James H. Harding.

Habitat and Habits In Michigan, Northern Leopard Frogs prefer marshes, meadows, and the grassy edges of streams, lakes, and ponds. Other habitats include bogs, sedge meadows, hay fields, damp rural yards, and even suburban lawns. Leopard Frogs wander much farther away from water than the closely related Pickerel Frog, and through this behavior may colonize newly opened habitats. When I lived in Illinois during the early 1960s in a newly constructed house, old cultivated land behind this house was bulldozed away, leaving ruts and crevices that Leopard Frogs immediately found and used for breeding purposes the next spring. During the rainy weather that occurred later in the season, we often found adult Northern Leopard Frogs in newly planted grass in our backyard, which faced the bulldozed area. Referring to the Great Lakes region, Harding (1997) related that Northern Leopard Frogs usually spend the winter in large ponds, lakes, and streams, where they sit on the bottom, hide under various shelters, or conceal themselves under layers of silt. In the early spring, these frogs move to shallower water to breed, sometimes traveling as far as half a mile or so from the winter site to reach these breeding sites. In the summer, these frogs tend to move into grassy meadows where they absorb water from dew or damp soil. In the fall they return to their winter sites.

2. Species Accounts

Ruthven et al. (1928, 61) reported that “the leopard-frog is the best known of the Michigan frogs because of its great numbers and its habit of traveling away from ponds in search of food. In midsummer it may be found in fields some distance from water. It can change color to a limited degree: when it emerges from hibernation it is very dark, almost black in color, but becomes lighter in a few days. Brown specimens kept in the laboratory in a dish containing moss turn green within a few days.” Minton (2001) reported that Northern Leopard Frogs in Indiana are usually found in marshes and bogs and in shallow ponds surrounded by wet meadows. Sometimes small sluggish streams as well as inlets of larger streams are habitats used by this species. During spring and fall they remain near the water, but as in Michigan, they move into grassland in the summer. In the Chicago area, C. H. Pope (1944) reported that in the summer, thousands of newly transformed Northern Leopard Frogs were sometimes seen, and he presumed they were migrating from rapidly drying sites where they had developed. In the 1960s near Lansing, Michigan, I commonly saw thousands of newly transformed Northern Leopard frogs early in the summer (and juveniles in the late summer or early fall) crossing country roads during warm, rainy nights. During these years, this was a predictable seasonal occurrence. In fact, these frogs on the road were often so abundant that cars would skid over the little creatures. I have not witnessed such occurrences recently. Reproduction and Growth In Michigan and the Great Lakes area, Northern Leopard Frogs move to their shallow breeding sites in the early spring, and the males begin to give their advertisement calls from positions sprawled on top of or just below the surface of the water. In Michigan, the peak of the breeding season is usually in April. Male Rana pipiens have two inflatable vocal sacs behind the mouth area, one on each side. These sacs inflate when the frogs call. Amplexus in Northern Leopard Frogs normally occurs in the evening, but sometimes this can be observed during the daylight hours. Harding (1997) stated that amplexed pairs of Northern Leopard Frogs will move to areas where other pairs of the same species have already deposited eggs.

Female Rana pipiens deposit about three hundred to six thousand eggs in masses that range from globular to flattened in shape. These masses are attached to submerged material such as twigs or stems. The communal egg laying that occurs in the Northern Leopard Frog may aid in heat absorption or be useful as a defense against excessive losses to egg-consuming predators. The eggs hatch within two or three weeks, and the larvae transform within two or three months. The new frogs are 20 to 30 mm (.79–1.18 in.) long. These froglets grow to maturity in one to three years, depending on environmental factors. Force (1933) studied growth in Northern Leopard Frogs in Cheboygan, at the north end of the Lower Peninsula of Michigan, and found that transformed frogs grew about 10 to ll mm (.39– .43 in.) in the first year after metamorphosis and increased in length about 7 mm (.28 in.) the next year. It was ultimately calculated that sexual maturity was attained at the age of three years after hatching in this northern area. Minton (2001) reported that the breeding season of Northern Leopard Frogs in Indiana starts in late March and lasts through April. Water temperatures where this species is breeding have been recorded between 50ºF and 61ºF. Calling males are usually heard at night or on rainy days. Egg clusters are roughly globular and consist of about three thousand to five thousand eggs that are laid in shallow water about 50.8 mm (2.0 in.) beneath the surface and are attached to plant stems or other such objects. The eggs hatch after a week or two, and the larval stage lasts two or three months. Diet In Michigan, Northern Leopard Frogs are said to feed mainly on insects (Harding and Holman 1992). In the Great Lakes region, terrestrial invertebrates are the main food of this species; this prey includes insects and their larvae, spiders, slugs, snails, and earthworms. Large adults will eat small vertebrates, such as Spring Peepers and Chorus Frogs (Harding 1997). Ruthven et al. (1928) stated that Rana pipiens in Michigan eat worms, insects, and small frogs. Remarks on the Northern Leopard Frog diet in Indiana are provided by Minton (2001, 140), who stated that “Leopard Frogs occasionally eat small vertebrates. At Fox Prairie in Hamilton County, I found one with the

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legs of a Spring Peeper protruding from its mouth and another with two Western Chorus Frogs in its stomach. Nearly all feeding seems to be done on land.” Predation and Defense Relative to Michigan, Harding and Holman (1992, 89) have stated that “Leopard Frogs and their tadpoles are eaten by a great number of predators, including fish, snakes, snapping turtles, larger frogs, hawks, herons, and mammals such as raccoons, minks, and otters. An adult frog will make long, erratic leaps to escape an enemy and, if grabbed, can emit a loud scream that might startle its attacker.” C. H. Pope (1944) related that Newts eat the eggs, and fish and aquatic insect larvae eat the tadpoles of the Northen Leopard Frog. He also stated that reptiles of several kinds, especially Watersnakes and Gartersnakes, eat both the tadpoles and the adults. He mentioned that humans and other mammals should be included among the “enemies” of this species. Interaction with Humans Leopard Frogs, especially Northern Leopard Frogs, have been used and abused more than any other North American anurans. At least in the past, bass and pickerel fishermen used “countless thousands” of young Northern Leopard Frogs as bait. To this effect, C. H. Pope (1944, 140) stated that “the demand is so great that the frogs can be bought by the dozen at all fishing stations and have been given special names, one of which is ‘policemen.’” A. H. Wright and A. A. Wright recorded an explicit Rana pipiens exploitation event that occurred in Spicer County, Minnesota, in 1930. In reference to a specific frog gatherer, they wrote that “he has seen them moving in such numbers at this season (first frost) as to form a band two rods wide and one-half mile long where no one could step without crushing frogs. . . . One night he and two other men picked up 750 pounds by hand” (1949, 490). In those days, small Leopard Frogs were used as fish bait and large ones were shipped to biological supply houses. Frogs in the millions, mainly Leopard Frogs, have been dissected in elementary courses in biology and zoology as a representative vertebrate, even though they do not come close to being typical vertebrates. But, as A. S. Romer (1959, 102) put it, “The choice of the frog as a favorite laboratory animal is due to several factors. One

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item (not a minor one) is the fact that it is common, readily available, and hence inexpensive.” Although they are relatively small, Northern Leopard Frogs have also been exploited for their legs, which are eaten by humans (the other parts being discarded). C. H. Pope (1944, 140) commented that “the individuals that escape the anglers and grow up are in danger of being collected for their legs, as this is one of the species relished by man and commonly seen in the markets of Chicago and other large cities.” Behavioral Characteristics For the behavioral characteristics of Northern Leopard Frogs, see the sections “Habitat and Habits,” “Reproduction and Growth,” and “Predation and Defense” in this account. Population Health This species is listed as a Species of Greatest Conservation Need in Michigan. An amazing decline of Northern Leopard Frogs has occurred not only in this state but throughout the Great Lakes region since the 1970s. This decline is especially striking because this species was if not the most abundant frog in the region certainly the most commonly seen before the 1970s. Oddly, the human exploitation of the species for fish bait, biological study, and frog legs (which, by the way, was going on during the time of great abundance of this species) had greatly subsided by the end of the 1960s. Certainly, other factors must be importantly involved. Loss and fragmentation of wetlands and adjacent meadowlands are undoubtedly important factors in the decline of this species throughout its range. Harding (1997) points out that the increased use of persistent pesticides is a suspected cause of the decline of the Leopard Frog. He also stated that experimental evidence indicates that Rana pipiens may be more sensitive than other native species of Rana to the effects of certain pesticides, but he also points out that additional research on the subject is needed. Leopard Frogs and their eggs are not tolerant of the acidification of their breeding ponds. Also, massive seasonal deaths are not uncommon in Northern Leopard Frog populations, and it has been suggested that these die-offs are related to disease or winter freezes and

2. Species Accounts

oxygen depletion. Red-leg disease is caused by various fatal bacterial infections that cause massive die-offs not only of Leopard Frogs in the laboratory but in natural populations as well. Population numbers of Northern Leopard Frogs have likely varied from year to year based on climatic factors, and when good Rana pipiens habitats become available, the species has the reproductive ability to rebound from previous population declines. Nevertheless, Northern Leopard Frogs in Michigan and the Great Lakes region are scarce or absent in many areas where they were formerly abundant, and the continued monitoring of these areas is necessary.

Rana septentrionalis Baird 1854 Mink Frog Identification As the Northern Leopard Frog resembles the Pickerel Frog in many ways, so does the Mink Frog resemble the Northern Green Frog. In fact, it is possible that the two may hybridize to an extent in the Upper Peninsula (see the Northern Green Frog account). The Mink Frog is found only in the Upper Peninsula of Michigan. Usually this frog has dorsolateral folds that are only partly complete or broken, or the folds may be absent. By comparison, the Northern Green Frog usually has complete dorsolateral

folds. The upper surfaces of the hind legs of the Mink Frog have lengthwise stripes or spots, whereas the legs of Northern Green Frogs usually have crossbands. When handled the Mink Frog gives off a pungent musky odor, which to some resembles the smell of a mink and to others rotten onions. This smell is not given off by the Northern Green Frog. I also detect on the skin of live Mink Frogs a rather gelatinous shine that I do not often see on live Green Frogs. I sometimes wonder if this odd shine is caused by whatever makes up the minky-smelling substance in the Mink Frog’s skin. Adult Mink Frogs in Michigan are about 50 to 76 mm (1.97–3.0 in.) in total length. The larva is dark green, in fact almost black, on its upper body (in alcohol) and deep yellow on its underside. It also has a dark throat. On the sides are black spots arranged on a lighter background. The muscular part of the tail is yellowish gray with large black blotches. The tail crests are a translucent yellowish gray with large black blotches. The upper lip has only one row of teeth, and the lower lip has three rows. The lower lip and both sides of the upper lip are bordered by papillae that are folded in at the corners of the mouth. The anal opening is on the right side of the body. General Distribution Mink Frogs are northern anurans that range from southern Labrador and the Maritime Provinces in Canada to Minnesota and southeastern Manitoba and

Fig. 64. Mink Frog (Rana septentrionalis) from Iron County, Michigan. Photograph by James H. Harding.

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south to northern New York and Wisconsin, with some isolated colonies in northern Quebec and northern Labrador (Conant and Collins 1998). Michigan Distribution The Mink Frog occurs in every county in the Upper Peninsula and on Isle Royale. Harding and Holman (1992) indicated that it also occurs on Drummond Island, but I am not able to substantiate this by any published reference. Costabile et al. (1993) have suggested hybridization may exist between Rana clamitans melanota and Rana septentrionalis in the Upper Peninsula, but this needs to be substantiated by genetic data. This species has not been recorded in the Lower Peninsula. Geographic Variation Describable variant populations of Rana septentrionalis in Michigan have not been identified, although the possibility exists that zones of hybrid or mimic populations of Mink Frogs and Northern Green Frogs may ultimately be detected. Habitat and Habits In Michigan, Mink Frogs prefer small, slow-moving streams where pickerelweed and other low emergent vegetation is abundant. Northern Green Frogs are much more ubiquitous in their choice of habitats (M. M. Hensley, pers. comm., 1967). Harding (1997) stated that Mink Frogs seldom leave the immediate vicinity of water but the juveniles sometimes move to other habitats during heavy rains. Mink Frogs winter in the mud at the bottom of the aquatic habitat in which they live. In the Great Lakes region, they start this period of dormancy in late September and often remain inactive into May. Relative to the Mink Frog in Michigan, Ruthven et al. (1928, 64) stated that “it has been found in streams, and even in the small pools which are formed at the base of uprooted trees. The species is said to be shy, but we have not found this to be true of Michigan specimens. When disturbed the frog dives quickly, but soon returns to the surface. The call is much like that of the woodfrog, a hoarse clack. When handled, it emits a strong, musky odor resembling that of the mink.” I have observed these animals several times in Michigan and, like M. M. Hensley, have found them in small, sluggish streams and their pools. Mink Frogs

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are easy to catch by hand compared to Northern Green Frogs; also, when hand held, Mink Frogs tend to be relaxed compared to Green Frogs. Perhaps this is because Mink Frogs are relying on their strong musky odor to effect a release by their predators. Reproduction and Growth In Michigan, the breeding time for Mink Frogs extends from early June through July (Harding and Holman 1992). Permanent water is needed for reproduction in this species. The male’s mating call may be described as a low “tok, tok, tok, tok,” which sounds like distant hammering. The males may call singly or in chorus, either by day or by night. The female lays from about one thousand to four thousand eggs in a somewhat rounded gelatinous mass. This mass becomes attached to vegetation below the surface of the water. The larvae are greenish brown with black spots and transform into frogs within a year or two. The newly metamorphosed froglets are about 30 to 40 mm (1.18–1.57 in.) long. Male Mink Frogs are sexually mature within a year or less, but females may take two years to reach breeding size (Harding 1997). Diet In Michigan, Mink Frogs are said to eat a variety of insects and other kinds of invertebrates, many of which are aquatic species (Harding and Holman 1992). Ruthven et al. (1928) reported that Mink Frogs in Michigan eat water insects and their larvae as well as small fishes. In the Great Lakes region, the diet of the Mink Frog is said to reflect its preferred habitat in that it consists mainly of aquatic insects and other invertebrates, such as whirligig and diving beetles, water boatmans, water striders, stoneflies, mayflies, blackflies, dragonflies, damselflies, spiders, and snails. Terrestrial insects trapped on the surface of the water are also eaten (Harding 1997). Mink Frog larvae feed on algae. Predation and Defense Harding (1997) reported that in the Great Lakes region, Mink Frogs are preyed upon by giant water bugs, herons, raccoons, and large Northern Green Frogs, which feed on both the larvae and adults. Leeches often parasitize Mink Frogs. On the “defense” side, Mink Frogs are said to be very alert, with any disturbance sending them clambering over the lily pads to the safety of open water, where they

2. Species Accounts

dive to the bottom and hide in the mud below. I have not found them to be so alert. The musky skin secretion of the Mink Frog obviously discourages some predators. Interaction with Humans I am not aware of instances in which Mink Frogs have been put on the end of a hook as bass or pike bait, gathered by biological supply houses to send to high school biology teachers, or separated from their back legs, which were then sent on to market in Chicago. This is all well and good, and the reasons must be partly their northern range, unpleasant odor, and slimy skins.

The body of Rana sylvatica is brown, reddish brown, or tan. A distinct white line on the upper lip usually extends to the end of the black mask behind the eye. The belly is white and sometimes mottled with gray. Some Wood Frogs have a light stripe down the middle of the back, especially in northern Michigan (Harding and Holman 1992). The length of the adults is said to range from about 34 to 83 mm (1.34–3.27 in.), but I have seldom seen Wood Frogs in Michigan that are even 2 inches long.

Behavioral Characteristics For the behavioral characteristics of Mink Frogs, see the sections “Habitat and Habits,” “Reproduction and Growth,” “Diet,” and “Predation and Defense” in this account. Population Health The Mink Frog is not on the Threatened or Endangered lists in Michigan. Harding (1997) mentioned that anecdotal reports indicate some Mink Frog populations may be declining, whereas Green Frogs appear to be maintaining their numbers or even increasing at the same sites. General Remarks The Mink Frog is one of the frog species in Michigan that cries out for all kinds of baseline ecological studies. Moreover, its relationship to the Northern Green Frog in the Upper Peninsula still needs to be unraveled.

Rana sylvatica LeConte 1825 Wood Frog Identification The Wood Frog can be characterized as a brown frog with prominent dorsolateral folds and a large dark mask behind each eye. This frog does not have external vocal pouches and is relatively short legged. It is the most singularly terrestrial adult ranid frog in Michigan, as other than a few short days at the breeding site, it spends all its active time on the woodland floor. Its skeleton is notably different from that of other Rana, especially in the region of the hip girdle (Holman 2003).

Fig. 65. Wood Frog (Rana sylvatica) from Grand Traverse County, Michigan. Photograph by James H. Harding.

Minton (2001) reported that Wood Frogs in Indiana seldom reach a body length of 2 inches and that the species is smaller in the northern part of the state. He found that in northern Indiana the mean length of eighteen adult males was 38.5 mm (1.52 in.) and the mean length of nine adult females was 43.8 mm (1.72 in.). In southern Indiana (“south of the Shelbyville Moraine”), he found the mean length of ten males was 47 mm (1.85 in.) and the mean length of eleven adult females was 52.6 mm (2.07 in.). He also reported that Wood Frogs from the lake plains of northern Indiana had shorter legs and more pigmentation on the ventral side of the body than those of southern Indiana. The larva is brownish gray with a few fine speckles of gold on its upper body and an iridescent grayish bronze below. The tail crest does not extend onto the body and is a light color vermiculated with dark. The upper lip has three rows of teeth, and the lower lip has four rows. The lower lip and the sides of the upper lip

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are bordered with papillae that fold in at the corners of the mouth. The anal opening is on the right side of the body. General Distribution The Wood Frog is found farther north than any other amphibian in North America, occurring from Labrador and northern Quebec in Canada south to Georgia and across through the entire Great Lakes region, Minnesota, northeastern Dakota, and through Canada to northern Alaska. Isolated populations in Alabama, Arkansas, Missouri, Wyoming, and Colorado may be relict populations from past colder times. Michigan Distribution The Wood Frog has been recorded from every county in Michigan. Rana sylvatica also occurs on Isle Royale and Bois Blanc Island, and on Beaver and North Manitou Islands in the Lake Michigan Archipelago. Harding and Holman (1992) incorrectly indicated on a map that this species occurs on Drummond Island and islands in the Lake Michigan Archipelago, other than those indicated above (see Bowen and Gillingham 2004). Geographic Variation Wherever the Wood Frog occurs in boreal and tundra areas, its hind legs are much shorter, and the animals are said to resemble toads, both in their overall appearance and their hopping gait. As far as I am aware, no distinct populations such as this have been recognized in Michigan. Thus far no subspecies have been named in the species Rana sylvatica, but one of the isolated populations in Colorado was once named Rana maslini (Porter 1969). This name was later rejected (see Crother 2008). Habitat and Habits The Wood Frog is an obligatory woodland floor dweller in Michigan. In southern Michigan it occurs in the broadleaf forest of floodplains, uplands, and farm woodlots; in the northern part of the state, it lives in both mixed conifer-broadleaf forests as well as pure stands of coniferous forest. When moist, shady woodlands are eliminated, Wood Frogs disappear. Adults are rarely encountered in water except during the short breeding season. I have noticed that when

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rainfall is normal or high in Michigan, these little frogs may occasionally be seen hopping about the woods in large numbers, especially during the earlier and later times of day. During dry spells they discontinue this activity and are very difficult to find. Harding (1997, 152) stated that “these frogs usually hibernate on land beneath loose soil, leaf litter, or decaying logs. They survive periods of subfreezing temperatures in winter by producing large amounts of glucose, which acts like a natural ‘antifreeze,’ causing ice to form in the extracellular spaces rather than within the body cells.” About Wood Frogs in Michigan, Ruthven et al. (1928, 152) stated that “it is found in thick wooded places among dead leaves and moss, where the dark brown or grayish coloring of the animals blends so perfectly with the surroundings that it is difficult to see. The black ear patch and the light line along the side of the head tend to break up the uniform coloration and thus also aid in concealment.” Relative to the Wood Frog in Indiana, Minton (2001) related that the species quickly disappears from farmlands and most suburbs. He stated that during most of the year this species is solitary and hides in rotting logs, piles of leaves, and other such cover, but that it sometimes becomes active both at night and in the daytime. C. H. Pope (1944) stated that the Wood Frog jumps astonishingly well when it is pursued and can turn in the air to land facing its pursuer. This ability is not known in its boreal and tundra relatives. Reproduction and Growth Wood Frogs breed quickly early in the spring, in a sort of breeding frenzy. In Michigan they breed from late March to early April, and the whole breeding season may last only five or six days. Mating often proceeds vigorously when snow is still present in the woods. The males give cluck-like calls that have also been described as sounding like ducks quacking in the distance (Harding and Holman 1992). Males outnumber females at breeding sites and seem to grasp at anything that looks, acts, or smells like another Wood Frog. I observed male Wood Frogs in a breeding frenzy during a snowstorm in southeastern Michigan in early April. There I witnessed two male Wood Frogs tenaciously holding an obviously dead Wood Frog in their grasp while other males clambered around the joined threesome. Harding

2. Species Accounts

(1997) reported that male Wood Frogs give a chirping release call when grabbed by other males but that females with unlaid eggs remain silent when grasped. Obviously the dead male I observed could not chirp and so was considered a female by the frantic males. When amplexus begins, the pair of frogs usually moves toward the center of the breeding pond, where the female deposits from about five hundred to three thousand eggs in rounded gelatinous masses that are normally attached to objects near the surface of the water. Sometimes several pairs of frogs will deposit their eggs in the same area. The length of incubation varies with temperature and ranges from as little as four days up to six to twelve weeks. The tadpoles transform in about six to twelve weeks. The new frogs range from about 10 to 12 mm (.40–.47 in.) in length. These froglets quickly leave the breeding site and enter the surrounding woods (Harding 1997). Males reach breeding size in one to two years, and females in two to three years. In Indiana, Minton (2001, 150) related that “calling males and freshly laid eggs were found in Perry County on March 6. Many eggs in the process of hatching were found in Clark County, March 28, and newly transformed young were found here May 29.” Relative to the breeding of this species in the Chicago area, C. H. Pope (1944) related that mating begins immediately when the frogs arrive at the breeding sites and occurs by day but becomes more active at night. The male grasps the female behind the arms and presses his thumbs into the chest of his mates. The female then releases the eggs within a few minutes. Pope also pointed out that Wood Frog eggs sometimes harbor algae and this gives the eggs a greenish hue, which no doubt aids in the development of the eggs. Diet Relative to the Great Lakes region, Harding (1997) stated that Wood Frogs feed mainly upon terrestrial invertebrates, which include beetles, crickets, caterpillars, spiders, earthworms, slugs, and snails. Juveniles are said to include a larger percentage of aquatic insects in their diets. The larvae feed on algae, diatoms, and rotting plant and animal matter, but they sometimes feed on the eggs and larvae of other amphibians. Ruthven et al. (1928) stated that captive Wood Frogs readily eat worms and insects and that the tadpoles live mainly on decaying animal matter.

In Indiana, Minton (2001) stated that Wood Frogs feed mainly on terrestrial insects and other arthropods and that worms and snails are occasionally eaten. He also mentioned that younger Wood Frogs eat a higher proportion of aquatic invertebrates than do the adults. In the Chicago area, C. H. Pope (1944, 109) stated that “the newly transformed wood frog’s food includes 13 per cent of aquatic forms, whereas that of the adult, as might be expected, is 98 per cent non-aquatic.” He went on to mention that Wood Frogs are mainly insectivorous but that they also eat millipedes, snails, and various other moderate-sized invertebrates. He also pointed out that in its feeding behavior Wood Frogs are more alert than many other frogs and that they may even walk or creep for some distance toward intended prey before making a capture. Predation and Defense In the Great Lakes region, Wood Frog eggs are eaten by invertebrate predators, including leeches and aquatic insects and their larvae. Newts are also fond of Wood Frog eggs. The larvae are eaten by diving beetles, water bugs, and the larvae of salamanders of the genus Ambystoma (Harding 1997). Tadpoles that are about to hatch, however, develop poison glands that repel some species of insects. Vertebrate predators of transformed Wood Frogs include larger Frogs, Gartersnakes, Ribbonsnakes, and Watersnakes as well as herons and other wading birds, raccoons, skunks, and mink. The skin secretions of metamorphosed Wood Frogs have been reported to repel shrews. The frantic and short early breeding time of Wood Frogs is probably an effective mechanism that saves many Wood Frogs from predation by snakes and other reptilian predators. Harding (1997, 153) reported that “when disturbed on land, they [Wood Frogs] will often make a series of erratic leaps and then freeze, sometimes seeming to disappear amidst the vegetation and leaf litter. When seized, a Wood Frog can give a piercing cry that might temporarily startle its attacker, allowing it to escape.” Interaction with Humans Murawski (2004) suggested that Wood Frog tadpoles subject to highway salt and brine runoff into ponds and wetlands near roads in Michigan had stunted

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growth, increased mortality, and caused morphological abnormalities. Wood Frogs, as far as I know, have seldom been used for fish bait, as a typical vertebrate for dissection in biology labs, or as edible items by humans. It has probably avoided these perils because of its small size, because people do not like to hunt for frogs in icy ponds, and because of its generally secretive habits later in the year. Population Health Wood Frogs are not protected as rare in Michigan, and as long as we protect moist woods and associated vernal ponds in the state, we should have plenty of Wood Frogs to listen to and watch. General Remarks Wood Frogs are another of the frog species that have the splendid physiological mechanism that allows them to survive freezing in the winter (Layne and Lee 1995; Lee et al. 1990). Studies on the geographic variation of Rana sylvatica requires detailed work in the future (Crother 2008).

Class Reptilia Reptiles have several adaptations for water conservation that are not present in modern amphibians, which usually have an aquatic larval stage and constantly lose water through their thin skins when on land. Most reptiles have a horny (heavily keratinized) skin that is almost always modified into scales or plates that reduce water loss. Reptiles also have advanced kidneys, with most secreting nitrogenous wastes in the form of uric acid, which is not only less toxic to them but requires less water loss than do the kidneys of amphibians. Also, some desert reptiles can tolerate high acid (urea) concentrations during times of drought. This tolerance allows them to minimize water loss. Finally, reptiles have evolved a shelled (amniotic) egg that provides a private pond (amnionic sac), food (in a yolk sac), and other membranes that facilitate respiration and waste removal. This egg adaptation, which occurred hundreds of millions of years ago, allowed reptiles to become true land animals by eliminating the necessity of an aquatic larval stage. Modern reptiles occur everywhere on Earth except the very coldest areas, such as Antarctica and the High Arctic, and diversity generally increases toward the equator.

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Order Testudines If turtles were known only as fossils, some large museums might pay as much to obtain their skeletons as they do for those of dinosaurs. In their evolution, turtles have literally turned their skeleton inside out (with the ribs external to the limb girdles) to perfect the characteristic protective shell. The earliest definite turtle fossils are known from the Late Triassic Period, about 220 million years ago, although turtle beginnings likely occurred considerably earlier. Though several ancestral lineages have been suggested, the direct ancestors of turtles have not yet been agreed upon. Turtles have attributes, which, as far as we know, are not shared or are extremely rare in other reptiles. For instance, turtle limbs have a very dense bone structure to support the heavy shell above. Other vertebrates tend to have hollow limb bones full of marrow where red blood cells are produced. To make up for the lack of red blood cell–producing marrow in the limb bones, turtles have large cavities inside the shell where red blood cells are produced and other cavities in the shell that allow this blood to be distributed throughout the rest of the body. The turtle shell is also a site of other important metabolic (regulatory) activity (Andrews 2000). Turtles are worldwide in their distribution except for the coldest regions. Although a northern border state of the United States, Michigan is blessed with four families and ten species of turtles, ranging from the very aquatic softshell turtles to the terrestrial box turtles. I must note here that all of Europe has only seven species of nonmarine turtles, and one of them, Trachemys scripta, was introduced from North America (Arnold and Ovenden 2002). Some of Michigan’s turtles are becoming rare while others remain relatively common. All should be treated with respect because they are a very significant part of our Michigan wildlife heritage.

Family Chelydridae The family Chelydridae is a New World family with a range extending from Canada to Ecuador. The family consists of two genera, Chelydra (Snapping Turtles) and Macrochelys (Alligator Snapping Turtles), each with one species in North America (although Chelydra extends into Central and South America). Both genera are large predatory turtles with a reduced shell, the lower shell (plastron) being especially reduced and cross-shaped

2. Species Accounts

(cruciform). The upper shell (carapace) has three keels, one central and two lateral (although the lateral keels are often obscure in adult Chelydra). The tail is long with three rows of prominent, elongated knobby scales along the top. The head is large with powerful jaws, and the upper jaw is hooked. The legs are large and bear heavy claws. One species and subspecies, Chelydra serpentina serpentina, the Eastern Snapping Turtle, is found in Michigan.

Chelydra serpentina serpentina (Linnaeus 1758) Eastern Snapping Turtle Identification The Eastern Snapping Turtle is by far the largest turtle in Michigan. It often reaches a weight of 4.5 to 16 kg (9.9–35.2 lb.). The record weight is 39 kg (85.8 lb.) in a captive individual (Harding and Holman 1997). As is characteristic for the family, the Eastern Snapping Turtle has a very large head with a hooked upper jaw. The carapace is relatively flat and may be black, brown, gray, or even olive. Young snappers have three keels on the top of their carapace, but these tend to flatten out in large adults. The plastron is reduced, exposing the legs and thighs. It is cruciform in shape. The legs are stout and have heavy claws. The tail is long and bears the three rows of thickened, elongated scales. Of interest is that snapping turtles of this species that live in such Deep South states as Louisiana and Florida do not tend to grow as large as those in northern states like Michigan, Wisconsin, and Minnesota, where relatively huge, “king of the pond” Eastern Snapping Turtles are not uncommon (Noah Anderson and Eric O’Neill, pers. comm., April 19, 2002). General Distribution Chelydra serpentina ranges from Nova Scotia, New Brunswick, and southern Quebec, Canada, west to southeastern Alberta, Canada, and southward east of the Rockies to southern Florida and the Texas coast in the United States; populations also occur in Veracruz, Mexico, and farther southward yet (with some breaks) through Central America to western Equador (Ernst and Lovich 2009). Some herpetologists consider the neotropical forms to consist of two additional species.

Michigan Distribution In Michigan the Eastern Snapping Turtle occurs in every county in the Upper Peninsula and on Beaver, Garden, and North and South Manitou Islands in the Lake Michigan Archipelago. It is found throughout the Lower Peninsula, although “official” vouchered museum records are not yet known for Emmet, Benzie, Oscoda, Ogemaw, Osceola, Clare, Gladwin, Arenac, Midland, Bay, Lapeer, and Macomb counties. They certainly occur in all of these counties, however. Geographic Variation No geographic variation has been found in Eastern Snapping Turtle populations in Michigan. A second subspecies, Chelydra serpentina osceola Stejneger 1918 (Florida Snapping Turtle) is recognized in the Florida Peninsula. At one time this animal was recognized as a full species.

Fig. 66. Juvenile Eastern Snapping Turtle (Chelydra serpentina serpentina) from Ingham County, Michigan. Photograph by James H. Harding.

Habitat and Habits I am not aware of any turtle species in eastern or midwestern North America that can take advantage of as many aquatic habitats as can the Eastern Snapping Turtle. The water in them just needs to be slow moving or still. In the Bloomington-Normal twin city area in north-central Illinois—part of the area the late Illinois herpetologist Philip W. Smith referred to as “the cornfield desert”—I saw one in the middle of summer, plodding along in a concrete water drain containing about two inches of water. In Indianapolis, a breeding

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population of Snapping Turtles existed in a thoroughly polluted creek near our house throughout the 1940s. In Michigan, Eastern Snapping Turtles existed in fair numbers in the Red Cedar River during the 1960s. As this river coursed through the MSU campus in the summer, it produced ugly odors, and campus physicians advised students to visit the infirmary if they happened to swallow the water or even fell in it and had any scratches on their body. Snapping Turtles are not uncommon in the Red Cedar today. They tend to occupy relatively deep holes in the river where the water is slow moving. Michigan Eastern Snapping Turtles are most common in slow-moving rivers, marshes, lakes, and ponds with muddy bottoms and dense plant growth, and they appear to be quite tolerant of organic pollution in these situations (Harding and Holman 1997). Snappers seldom bask, but they often travel overland when they are nesting or looking for better habitats. In the Great Lakes region snappers usually spend their daylight hours buried in the mud or in weed beds, or hidden under logs or other cover. These animals are able to swim, but they spend most of their time walking on the bottom. When the water gets warm in the summer, snappers often are most active in the morning and early evening, and sometimes become nocturnal (Harding 1997). In the winter these turtles may dig shallowly into the mud, push under overhanging banks, or sometimes just sit on the bottom of their aquatic habitat, at times congregating in numbers. It is not unusual to see an Eastern Snapping Turtle crawling slowly about under the ice. Winter dormancy of these animals in the Great Lakes region usually occurs from about mid-October to early April. Meeks and Ultsch (1990) studied hibernating Snapping Turtles in Ohio and found that the hibernacula preferred by the snappers needed to have some combination of the following factors: water that is shallow enough for breathing at the surface without having to spend swimming energy to do so but deep enough so they will not freeze at the bottom; a place that will be a likely spot to freeze over last and thaw first; mud deep enough to allow a turtle to bury itself; and some additional type of cover, such as an overhanging bank. In the 1950s, in Brown County in south-central Indiana during July, I observed two local turtle hunters

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catching large snapping turtles by a process they called muddling. This consisted of reaching into undercut banks barehanded and pulling the turtles out, seemingly by any way they could get hold of them. As a fifteenyear-old, I marveled at both the dexterity and what I considered the reckless behavior of these gentlemen. But they assured me that “snappers underwater don’t usually bite.” I saw these men catch several turtles without losing a pinky. I imagine these turtles were congregating beneath ledges because of the hot spell that we were having at the time, and that the local turtle hunters were on to this behavior. Indiana herpetologist Sherman A. Minton (pers. comm.) related that he was aware that turtle hunters in northern Indiana located snappers by probing likely spots with their hands. No matter how Eastern Snapping Turtles behave underwater, there is no question that on land they will bite viciously and repeatedly at any intruder, including humans, often launching their whole body partially off the ground during each attempt to get hold of whatever is threatening them. Reproduction and Growth Eastern Snapping Turtles in Michigan may mate anytime during their active period, but mating usually peaks in the spring and fall. Mating occurs underwater. Ernst and Lovich (2009) report that this species mates from April to November. The following account of mating in Chelydra serpentina is modified from Ernst and Lovich (2009), Harding (1997), Legler (1955), and Taylor (1933). In a mating situation without courtship, a male may either mount a submerged female at once or pursue her for several minutes and mount her near the surface of the water. Mounting involves the male grasping the edges of the female’s carapace with his strong set of claws. If a courtship sequence is involved, males and females face one another on the bottom with their necks extended so their snouts are almost touching. During this approach the back ends of both animals are elevated and the front ends of the plastra are touching the bottom. At this point the two turtles may swing their heads and necks back and forth sideways and then bring them slowly to the straight-on position. Another courting situation has been described in which the head-to-head snappers gulp water and expel it so violently that a current of water rushes above their heads.

2. Species Accounts

When the male has successfully mounted the female by grasping her carapace with all four claws, he curls his tail under her body and at the same time extends his chin over her snout to keep her head in her shell. He then begins muscular contractions of his legs, neck, and tail. His neck is thrust forward and downward at this time. He may also bite the female’s head and neck or grab a loose fold of her skin. He uses his muscular tail to elevate her tail, thus improving cloacal (posterior opening to her body) contact. When the penis of the male is inserted into the female (intromission), muscular spasms ensue that presumably are associated with sperm transfer. The female is said to usually be passive after she is mounted, except that if she is bitten she may bite back. The sperm that is introduced in a single mating in Chelydra serpentina may be capable of producing fertile eggs for several years. In Michigan and the Great Lakes region, nesting usually occurs from about late May through early July. In Michigan it usually peaks about the middle of June, but cold early summer weather can postpone this endeavor. Female snappers in Michigan usually lay a single clutch per year and during cold summers may actually miss a year. Harding (1997) mentioned that females may travel a kilometer (.62 mile) or more from water to find a proper nesting situation. Unfortunately, this leads to many Michigan snappers being killed on roads while going to or traveling back from their nesting sites. The females of this species prefer open, sunny locations where moist sand or loose soil occurs; they will often start and then abandon holes before finally finishing a suitable one. In Michigan, I have seen snappers nesting along roadsides, on open sandy banks, and in the yards of lakeside cottages and suburban houses. At the MSU Museum we frequently get calls from excited people who have Snapping Turtles nesting in their yards. These people almost always let these turtles finish their job and crawl away and then eagerly monitor the nest until the little ones appear. Many times they gather up the babies and release them in suitable habitat. This is good for the local turtle population, for the hatchlings may become dried out in the sun, eaten by predators, or run over by cars (especially in suburban areas) before they reach a suitable aquatic site. The nests of Eastern Snapping Turtles are usually somewhat flask-shaped and are dug by the hind feet of the females. After depositing about 25 to 50 or more

eggs (the record is 109), she uses her hind legs to refill the nest and then heads back to the water. This process can take several hours. Snapping Turtle eggs are round and about an inch (25.4 mm) in diameter. These eggs, which have been described as looking like Ping-Pong balls, have rigid shells that become flexible after several days of absorbing water. In many kinds of turtles, including several species in Michigan, the sex of hatchlings is not genetically determined as in humans but is determined by the incubation temperature of the eggs. This is called temperature-dependent sex determination (TSD). The most common situation is for males to result from cooler egg temperatures and females to result from warmer temperatures. The exceptions to this general rule are numerous. TSD influences the structure of turtle populations in many ways, and ongoing studies and interpretations of TSD are going on at a fast pace. Chelydra serpentina has TSD, and it is quite complicated. Ernst and Lovich (2009) have summarized the work of several authors to show how sex ratios in snappers change as incubation temperatures change. Snapper eggs incubated at 20ºC (68ºF) produce only females; eggs incubated at 21 to 22ºC (69.8–71.6ºF) produce both male and female hatchlings; eggs incubated at 23 to 24ºC (73.4–75.2ºF) produce only males; eggs incubated at 25 to 28ºC (77–82.4ºF) produce hatchlings of both sexes but mainly males at the lower end of this range; and finally, eggs incubated at 29 to 31ºC (84.2– 87.8ºF) produce only females. More information about TSD and temperature-sensitive embryological stages in Chelydra serpentina may be found in Ernst and Lovich (2009). The eggs that survive hatch in about 55 to 125 days, depending on temperature, moisture, and other climatic variables. The hatchlings are black and about 25 to 38 mm (.98–1.5 in.) in shell length. In Michigan, female Eastern Snapping Turtles reach sexual maturity in eleven to sixteen years, and at that time they have a carapace length of about 203 mm (8 in.). In a study of reproduction and nesting ecology of the Eastern Snapping Turtle at the E. S. George Reserve in southeastern Michigan from 1978 to 1983, Congdon et al. (1987) found that the mean egg clutch size over six years ranged from 12 to 41, with the average clutch size being 27.9 eggs. Females in these populations produced

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only one clutch each year. The youngest reproductive female of known age was twelve years old. The length of the reproductive season was from thirteen to thirtyone days. The beginning of nesting in this species was related to the amount of heat that was available during March, April, and May. Nest locations were an average distance of 183 meters (600.24 ft.) in a straight line from the nearest relatively permanent water. Interestingly, there were essentially no differences between length of distance from water and the amount of nest predation that was incurred. Females traveled as far as 1,625 meters (5,300 ft.) in a straight line during nesting preparation. Congdon et al. (1987) also found that destruction of nests by predators averaged 70 percent and ranged from all nests being destroyed in each of two years to a one-year low of 30 percent. Most nest predation occurred within twenty-four hours after the nests were constructed, and the major predators were raccoons and foxes. They found that nests preyed upon by foxes were both farther from water and older than those disturbed by raccoons. In nests that escaped predation, an average of 4.14 developing embryos died in the nest. The dates of the emergence of hatchlings ranged from late August to early October, with the average number of days from egg laying to the emergence of hatchlings being 93.2. Juvenile snappers have grasping ability in their long tails, and Brodie (1958) reported that they would grasp a stick with their tails and could hang on for several minutes. It has been suggested that the long tail of hatchlings could grasp objects that would allow the turtles to keep their head out of the water (R. J. Brooks to Ernst et al., pers. comm., 1994). Relative to growth, Gibbons (1968a) studied young Eastern Snapping Turtles in a polluted stretch of the Kalamazoo River near Otsego, Michigan. The mean carapace length for five specimens increased 32 mm (1.26 in.) per year for five years from the first year through the sixth year of growth, and there was no indication that this growth rate rapidly slowed once maturity was reached. Adult female Snapping Turtles in Ontario have an average life span of forty years (Galbraith and Brooks 1989). This longevity may be associated with the large size attained in these turtles in northern areas.

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Diet Lagler (1943) conducted a seminal study on the food habits and economic relations of Michigan turtles, including Eastern Snapping Turtles. Bodies of water inhabited by turtles were studied throughout the state and included the following kinds of situations: northern lakes, southern lakes, river-mouth lakes, fish hatcheries, trout streams, and non-trout streams. The purpose of this research was to study turtles in relation to fish management, but such thorough studies of turtle feeding habits in North America are rare. An annotated list of vertebrate food found in 323 Eastern Snapping Turtles did include fishes, which consisted of brook trout, brown bullhead, yellow bullhead, pickerel, northern pike, yellow perch, smallmouth bass, largemouth bass, bluegill, pumpkin seed, rock bass, golden shiner, common shiner, blacknose shiner, mud minnows, Johnny darter, Iowa darter, and fantail darter. Fish eggs were also found. Vertebrates other than fish found in snappers included Common Mudpuppy, American Toad, American Bullfrog, Pickerel Frog, Eastern Musk Turtle, Eastern Snapping Turtle, Blanding’s Turtle, mallard, teal, Florida gallinule, muskrat, and eastern meadow mouse. Material designated as carrion included bluntnose minnow, yellow perch, largemouth bass, rock bass, bluegill, black crappie, bits of Blue Racer, Musk Turtle, and European starling. Invertebrates in snapper stomachs included a few bits of freshwater sponge material, an earthworm, a tubicifid, and four leeches as well as crustaceans, water mites, insects, snails, and clams. Various types of algae and the remains of aquatic rooted plants had also been ingested by the turtles. A summary of food contained in 173 stomachs and 261 colons of 281 Eastern Snapping Turtles collected from natural waters (fish hatcheries were left out) led Lagler (1943, 277–78) to state that “considering only the stomach contents, game and pan fishes, carrion and plants appear as the most important foods of this turtle. On the basis of stomach contents about one-third of the food of the snapping turtle in Michigan is composed of game and pan fish. Another third is composed of vegetable matter, almost entirely the leaves and petioles of aquatic plants, eaten by three out of every four individuals. The remaining third is largely the remains of dead animals but includes significant quantities of crayfish, snails, and insects.”

2. Species Accounts

Lagler (1943, 306) concluded that “snappers were not found to be serious predators of young waterfowl even in a sanctuary lake and the assertion of many previous workers in regard to waterfowl–snapping turtle relations are regarded as overstatements.” I think we must accept the fact that Eastern Snapping Turtles do feed on game and pan fish, but other factors must be considered. Other fishes such as muskellunge, northern pike, pickerel, largemouth bass, smallmouth bass, channel catfish, garfish, and bowfin, all large predators like Snapping Turtles, feed on other fishes, including other game and pan fishes. One might suggest the removal of garfish and bowfin (both native species) from lakes (I would not be for this because they are both very interesting species and part of the ecosystem where they occur) because they are not of commercial value. But why consider removing snappers, which, like game fishes, have a definite ecological and food value in Michigan? Ernst and Lovich (2009) reported that young snappers actively hunt for food but that older ones often wait in ambush for prey. Small prey is quickly gulped down, but larger prey is held in the mouth and torn apart with the claws. The turtles usually feed underwater, but they can also feed on land. Ernst noted that he has seen two large adults feeding on plant shoots (Carex) on land. In Michigan, Eastern Snapping Turtles, like some other turtles, learn to congregate around quiet water areas where people fish from the bank for pan fish. The turtles especially seem to come when groups of anglers congregate in certain areas and throw gill-hooked, undersized bluegills or pumpkinseeds (sunfish) back in the water to die. One or two very large turtle heads are usually visible nearby, and the turtles pick off one by one the mortally wounded fish. The suck-and-gape feeding mechanism of these turtles creates a characteristic gulp and swirl unlike the “pops” and “boils” that appear when fish are feeding. In suck-and-gape feeding, the snappers (and other kinds of turtles) open the mouth at the same time they quickly lower the throat, thereby sucking in their prey. Predation and Defense Most predation on Eastern Snapping Turtles affects nests and hatchling and juvenile individuals. Raccoons and foxes are top predators of snapper eggs in Michigan, and Ernst and Lovich (2009) list, in general, Hog-nosed

Snakes, crows, bears, mink, and skunks as additional nest predators of snappers. Hatchling and juvenile snappers are eaten by raccoons, egrets, bitterns, shrikes, crows, hawks, bald eagles, bullfrogs, watersnakes, alligators, and larger snapping turtles. Full-grown snappers have few predators to worry about in their natural habitat except humans. Juvenile Eastern Snapping Turtles are protected by their dark coloration that blends in with the mud, dead leaves, and logs on the bottom of a lake or pond; by their immobility; and by the unpleasant secretions from their musk glands. If poked or picked up on land, they become rigid and release a foul-smelling musk. I thought the first baby snapper I picked up as a youth was dead, and so have many other people I have spoken to about this subject. Adults, on the other hand, especially on land, will lunge and snap at anything that annoys them. I have been bitten only once by an Eastern Snapping Turtle, and the bite happened completely by surprise. Years ago while in the service near Memphis, Tennessee, I was fishing in a farm pond. Sitting happily on top of a galvanized minnow bucket hoping to catch a catfish, I felt a sharp pain in my rear and discovered an eight-inch snapper hanging on my blue jeans and a “pinch” of skin just beneath. As I stood, the snapper dropped off and continued straight to the water amidst a hail of fourletter words that I had acquired in the Navy. It was late May, and the attacker must have been a female returning from her nesting site. My only guess for the reason of the attack was that I was blocking her straight-line route back to the water. Decades ago I started removing all turtles from roads whenever I thought I could do safely. Snapping turtles are a problem in such situations, as they strike out viciously at any helping hand. It’s fairly easy to get one into a large net, but getting it back out is a problem. Dragging them off the road by the tail has worked for some people, but doing that may cause the tail vertebrae to separate, and that can result in serious consequences for the turtle. Harding and Holman (1997, 14) addressed this problem by explaining that “the only safe way to carry a large snapper is to grab the base of the tail, making sure the head is pointed away from your body and other people. This method can injure the turtle’s tail vertebrae, however, and a miscalculation could result in injury to the handler as well. It is best to leave all of these animals

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alone whenever possible.” I have one last bit to add. If you have some rigid article in your car, such as a broken broomstick, or can find a tree branch of similar size, you can tease a turtle until it grabs the stick, and then you can sometimes slide moderately large snappers off the road and onto the shoulder. Whether snapping turtles bite when underwater, Harding and Holman (1997, 14) also explained that “when under water, snapping turtles rarely bite unless restrained, preferring instead to hide in the mud or swim away.” Minton (2001, 166) stated that “snappers usually do not try to bite while in the water.” Ernst and Lovich (2009) mentioned that Snapping Turtles are usually docile when submerged but point out that even then they can and sometimes do bite viciously. Interaction with Humans Snapping Turtles are pursued for food in Michigan. There are size, bag, and possession limits; trapping regulations; and a closed season during which turtles can breed and lay their eggs. Unfortunately, many of the state’s populations of snappers have been reduced by commercial exploitation (Harding and Holman 1997), although the ending of commercial turtle trapping in Michigan in 2008 may allow over-harvested populations to recover. However, the state regulations on taking amphibians and reptiles often seem to be ignored by fishermen. These regulations are printed in detail in the MDNR Michigan Fishing Guide regulations booklet, which is free wherever Michigan fishing licenses are sold as well as on the MDNR website (www.michigan.gov/dnr). Snapping Turtle flesh is eaten throughout the turtle’s range, and it is tasty when properly prepared. It makes a particularly excellent soup. The fresh eggs of this species are also edible; they can be fried but will not hard boil (Ernst and Lovich 2009). Harding (1997) makes a good case for Eastern Snapping Turtle conservation in the Great Lakes region. He points out that the eggs and young of these animals provide a considerable food resource for a variety of predators, whereas the adults play a role as both predator and scavenger. He also states that commercial trapping may lead to local population declines if the trapping is not carefully managed. Serious doubts have been raised as to whether Eastern Snapping Turtles can be commercially harvested on a sustainable basis, since their population stability is dependent on

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the long-term survival of an adequate number of breeding adults. Congdon et al. (1994) did research on a population of Eastern Snapping Turtles at the E. S. George Reserve in southeastern Michigan from 1975 through 1992. They found that it was eleven to sixteen years before female snappers reached sexual maturity, which of course means that a large portion of their life span is spent not adding small turtles to the population. However, the study showed that population stability was most sensitive to changes in the survival rate of both the juveniles and adults and was less sensitive to changes in age at sexual maturity, nest survival, or the number of eggs produced per season. A rather foreboding conclusion of the study is that an annual mortality of 10 percent in adults more than fifteen years of age would reduce the number of adults by half in less than twenty years. Congdon et al. (1994, 397) note that “successful management and conservation programs for long-lived organisms will be those that recognize that protection of all life stages is necessary. Without protection of adults and older juveniles, programs that protect nests and headstart hatchlings have a low probability of success. Carefully managed sport harvests of turtles or other long-lived organisms may be sustainable; however, commercial harvests will certainly cause substantial population declines.” Behavioral Characteristics In this account, behavioral characteristics are described in the sections “Habitat and Habits,” “Reproduction and Growth,” “Diet,” “Predation and Defense,” and “Interaction with Humans.” Legler (1956) saw Painted Turtles (Chrysemys picta) basking on the backs of Snapping Turtles floating on the water surface. This behavior would presumably be somewhat risky for very small Painted Turtles. General Remarks On Memorial Day in 1974, I found a very small juvenile Eastern Snapping Turtle lying on a sand bank on the Flat River near Belding, in Ionia County, Michigan. A local fisherman looked at the stiff, smelly creature and muttered that he had come across dead baby snappers before on sand banks in the area. I took the animal home and raised it in a tank. It was a voracious feeder, and I had to remove it time

2. Species Accounts

and again from the tank to change its water. In July 1980 I released it in a pond near Battle Creek. It had a carapace length of 167.4 mm (6.59 in.) at the time. During all the years in captivity, the turtle was completely docile and never showed any hostile movements toward me or anyone else who handled it. Others who have raised hatchling or juvenile snappers have had the same experience, but I am not aware of any who have raised one to such a size. I now wonder what triggers the vicious attack mechanism of snapping turtles and how, why, and when it is recorded in their brain. Probably the ability to develop a biting defense is present from hatching and becomes most evident once the turtle reaches a size at which an aggressive posture can be an effective response to a predator. Being raised in captivity, where the presence of humans means food and not danger, may dull these innate defensive instincts. An abundance of filamentous green algae characteristically grows on the the carapace of Eastern Snapping Turtles in a symbiotic (mutually helpful) association that serves not only to help conceal the turtle but also as a fine substratum for the alga’s attachment. According to Wooten (1999), scanning electron microscopic studies of snapper shells suggests that compared with other turtles the more microlayered structure of the snapper shell favors the filamentous attachment of the green algae.

Family Emydidae The Family Emydidae (New World pond and river turtles) is very diverse, one whose members occur in a variety of habitats. But they occur most abundantly in permanent freshwater lakes, ponds, rivers, and streams in temperate lowland regions in North America (where they are most abundant), with one genus (Emys) that occurs in North Africa, southern Turkey, the Middle East, and throughout Europe as far north as Denmark, Germany, and southern Russia. Most emydids have some webbing on the toes, and a few have a single hinge on the plastron. Most emydid species, whether aquatic or terrestrial, have a basking habit. Moreover, many species have rather elaborate courtship rituals. They range in size from the small Bog Turtle, Glyptemys muhlenbergii, which is normally less than 10 cm (4 in.) long, to the large Gray’s Slider, Trachemys venusta grayi, of Guatemala, which may reach 60 cm (23.62 in.) in length. Michigan is fortunate to have seven species of emydid turtles within its boundaries.

Chrysemys picta (Schneider 1783) Painted Turtle (composite range of intergrading subspecies) Identification Painted turtles are by far the most common turtles in the state and have been designated the state reptile of Michigan. They are attractive turtles, being a moderately small, dark-shelled species with a yellow-striped head and red- and yellowstriped neck, legs, and tail. Males are smaller than females but have much longer front claws. The smooth black or olive-colored carapace has red markings along the edge. The plastron is light yellow and sometimes tinged with red or orange. Unless the animals are very old, it’s usually possible to detect the outline of the bones of the plastron through the semitransparent epidermal scutes of the plastron. The plastron also bears a dark, central blotch that differs in size and shape depending on the subspecies involved. The adult carapace length is about 10 to 18 cm (3.94–7.09 in.). General Distribution The range of Chrysemys picta in North America is extensive. They occur, with some substantial gaps in the more arid regions, from coast to coast through the northern United States and southern Canada southward to New Mexico and the Gulf of Mexico from northwestern Florida to Louisiana (see Conant and Collins 1998, 185, map). Michigan Distribution The Painted Turtle has been officially recorded (with museum-catalogued specimens) from every county in the Upper Peninsula of Michigan except for Baraga County, and they undoubtedly occur there as well. It also has been recorded from Isle Royale and Drummond Island, and from Beaver, Garden, High, and North and South Manitou Islands in the Lake Michigan Archipelago. Painted Turtles are widespread across the Lower Peninsula of Michigan; museum records are presently lacking for some counties around Saginaw Bay and in the thumb area, including Bay, Tuscola, Sanilac, and Lapeer counties, as well as Benzie, Van Buren, Monroe, and Macomb counties. All of these counties certainly have populations of Chrysemys picta, however.

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The Amphibians and Reptiles of Michigan

FIG. 67. Midland Painted Turtle (Chrysemys picta marginata) from Kalkaska County, Michigan. Photograph by James H. Harding.

Geographic Variation Two subspecies of Chrysemys picta occur in Michigan, and they interbreed broadly across the Upper Peninsula. Chrysemys picta marginata (Agassiz 1857), the Midland Painted Turtle, occurs throughout the Lower Peninsula and also has been identified from the eastern and central Upper Peninsula. Chrysemys picta bellii (Gray 1831), the Western Painted Turtle, occurs in the far western part of the Upper Peninsula. In between in the UP, many Painted Turtles are intermediate between the Midland and the Western Painted Turtles. Several characters distinguish the two subspecies, but the field mark most frequently used for this purpose is an elongated dark blotch on the center of the plastron. It is smaller and relatively unelaborated in the Midland Painted Turtle and more extensive with undulating borders following the plastral scute seams in the Western Painted Turtle (see fig. 68). Ernst and Fowler (1977) studied Chrysemys picta at localities across the Upper Peninsula of Michigan on the basis of the (1) seam disalignment in the carapace, (2) blotch pattern on the plastron, (3) reticulate pattern on the carapace, and (4) width of the second pleural seam on the carapace. Treating this data statistically, they were able to identify “pure” C. picta bellii from only two counties, Ontonagon and Houghton, in the extreme western part of the Upper Peninsula, and C. picta marginata from Chippewa and Luce counties in the eastern part of the UP. All of the sites in between had intergrade populations between the two subspecies.

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Two other subspecies of Painted Turtles are presently recognized, C. p. picta (Eastern Painted Turtle) in the eastern United States and C. p. dorsalis (Southern Painted Turtle) in the lower Mississippi River valley. The classical explanation for the current four subspecies of Chrysemys picta is that after the Pleistocene Ice Age, the Southern Painted Turtle spread up the Mississippi River and met the Western Painted Turtle population near the

FIG. 68. Plastron of a Midland Painted Turtle (Chrysemys picta marginata) from Kalkaska County, Michigan (same individual as in fig. 67). Notice the small, elongated blotch in the middle of its plastron that distinguishes it from the Western Painted Turtle, which has a much larger blotch. Also notice the roughly oval shape of the entoplastral bone that is outlined beneath the epidermal scutes. This shape is characteristic of Painted Turtles. Photograph by the author.

2. Species Accounts

mouth of the Missouri River. Hybridization of these two turtles produced the Midland Painted Turtle, which spread up the Ohio River valley into the eastern Great Lakes region. Meanwhile the Eastern Painted Turtle spread northward along the Gulf Coastal Plain, to finally meet the Midland Painted Turtle in the north and the Southern Painted Turtle in the west (Bleakney 1958). Harding and Ewert (2001) tested the portion of the Bleakney hypothesis that states the Midland Painted Turtle originated as a postglacial intergrade between the western C. picta bellii and the southern C. picta dorsalis. These two subspecies were purposely crossed in an enclosed outdoor research area. All of the characters that were present in the intergrade hatchlings resembled those of the Midland Painted Turtle, although the hatchlings had a slightly more prominent stripe in the middle of the carapace (middorsal stripe) than is typical of the Midland Painted Turtle. The authors came to the conclusion that “Bleakney’s hypothesis is considered to be not falsified [proven wrong] by this study” (79). Other explanations for the present distribution of the subspecies of Chrysemys picta have been offered; see the discussion in Ernst and Lovich (2009, 187–88). Habitat and Habits Painted Turtles in Michigan are most often found in ponds, lakes, swamps, and marshes as well as slowmoving stretches and backwaters of rivers and streams. They prefer habitats with shallow water and a soft, muddy bottom along with ample aquatic vegetation. Painted Turtles need tussocks, logs, lily pads, mats of vegetation, or even junk to bask upon. They are very mobile reptiles, and when a new farm pond is dug, they often show up within days. They are able to tolerate moderate levels of pollution, and populations persist in many urban environments. In a seminal study, Sexton (1959) divided the yearly activity of the Midland Painted Turtle in Michigan into separate seasonal sequences. The prevernal sequence begins with the final melting of the ice and lasts until March 25, or when mass movements out of hibernation occur in the species. The vernal sequence occurs from March 16 to May 31, or when aquatic plants important to the species appear on the surface and most C. picta breeding occurs. The aestival sequence is from June 1 until August 31 and begins with the nesting season and

ends when the animals move into their winter habitats. The autumnal sequence extends from September 1 until December 1 or when the ice becomes permanent. Finally, the hiemal sequence covers the interval when the pond is permanently covered with ice. Little activity is reported to occur during the prevernal sequence. Males can be seen pursuing females during the early part of this sequence. This pursuit can be observed because yellow marks behind the turtles’ eyes are visible even in somewhat brown or tea-colored water. In the aestival interval that comes after the breeding season, the turtles move back into the hibernating ponds, which, by this time, are usually grown over with duckweed and other aquatic vegetation. At this time, it’s most typical to see many Painted Turtle heads, some with adherent bits of duckweed on them, poking out at the surface. Painted Turtles are said to move out of the vegetation into deeper water during the autumnal season, and they enter into dormancy during the hiemal season. Painted Turtles spend a great deal of time basking, especially during the interval between the end of hibernation and active breeding. In a small woodland pond north of Lansing, I have counted up to fortyeight individuals on one set of four logs in April. It appears that in early April these individuals will bask continuously from early morning to late afternoon. After April the number of baskers begins to decline. In Ontario, Canada, Schwarzkopf and Brooks (1985) found that 21.4ºC (70.5ºF) is considered to be an “operational level” temperature for Painted Turtles. These authors report that two types of basking, unimodal and bimodal, occur in Ontario. The unimodal activity pattern consists of a rise in basking activity until noon, with a decrease in this activity in the afternoon. The bimodal basking pattern consists of a drop in basking in the middle of the day and a rise in the late afternoon. On days when bimodal basking occurs, fewer Painted Turtles bask per hour, the first basking peak occurs earlier, and the environmental temperatures are warmer than during unimodal basking periods. Painted Turtles, particularly tiny hatchlings, may overheat and die. I have found badly dehydrated or dead hatchling Painted Turtles on blacktop roads in southern Michigan on hot summer days. These animals were evidently attempting to disperse to moister situations. I have been able to rehydrate some by placing them

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The Amphibians and Reptiles of Michigan

in shallow water. The critical maximum temperature for Midland Painted Turtles in Michigan is 42.2ºC (107.96ºF) (Hutchison et al. 1966). Hatchling Midland Painted Turtles often overwinter in the nest. One of the earliest reports of this situation was made by Hartweg (1946), who studied the nest of a Midland Painted Turtle near a swamp in Washtenaw County, Michigan. The eggs were laid June 18, 1944, and seven turtles had hatched by October. On March 25, 1945, six of the seven were at the ground surface, and one was still in the nest. All seven hatchling turtles still had egg teeth. Later, Storey et al. (1988) demonstrated that Painted Turtles could actually survive freezing in the nest during winter hibernation. Perhaps even more striking is the fact that Painted Turtles can survive underwater all winter without breathing. Both Painted Turtles and their relatives the pond sliders (Trachemys scripta) have by far the greatest demonstrated tolerance of any vertebrates for a total lack of oxygen (Storey and Storey 1992). When these turtles go beneath the water, the oxygen content of their blood falls quickly to near zero, a situation that would be fatal within a few minutes to humans. In Painted Turtles and pond sliders, however, very complicated, interacting metabolic adaptations that lead to a quick lowering of energy requirements save the turtles from death. In Michigan and the entire Great Lakes region, Painted Turtle hibernation occurs underwater in or on the substrate at the bottom of aquatic situations where they stay dormant from about October or November through late March or early April (Harding 1997). Crawford (1991) studied a Midland Painted Turtle hibernation site near Ann Arbor, Michigan, from 1981 to 1985. Hibernating turtles at this site encountered minimum water temperatures of from 3.7 to 6.3ºC (38.66–43.34ºF). Ice covered the site for an average of ninety-two days per year. Dissolved oxygen became severely limited for an average of forty-three days each year. In the various years, these turtles came out of hibernation from March 1 to April 14, depending on how severe the winter was. The turtles in this study usually emerged after the winter’s ice was completely gone and temperatures at the bottom were rising. In northern populations of Painted Turtles, the water at hibernation sites may be 2 m (6.56

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ft.) deep (but it is usually less), and the animals may bury themselves as deep as 95 cm (37.4 in.) (Ernst and Lovich 2009). Homing ability is well documented in the Painted Turtle (e.g., Cagle 1944; Emlen 1969; Ernst 1970a; and Vogt 1981). Williams (1952) also studied homing in the Midland Painted Turtle in a small lake in southern Michigan where he marked ninety-eight members of the population and transported them to a single site. Forty-one of these turtles returned at least one time to the place from which they were originally taken. One individual returned to the capture site fifteen times within twenty-nine days. During May to August in 1999 and 2000, Rowe (2003) studied the home ranges and movements of Chrysemys picta marginata from a small marsh system on Beaver Island, Michigan. Here, based on radiotelemetry, he found that male and female home ranges were similar in size. He also discovered that most individuals preferred one or two core areas within their home range. The total daily distance moved per day by these turtles averaged 68.1 m (223.4 ft.) for the entire study. But in 2000 the average movements per year were more than twice the distance they were in 1999. Moreover, the average home range in 2000 was more than twice as large as in 1999. These differences in 2000 were probably caused by low precipitation, which shrank the marsh. Congdon et al. (1992) conducted a habitat study of Midland Painted Turtles in a marsh on the E. S. George Reserve in southeastern Michigan. They reported that younger and smaller Painted Turtles were more likely than older and larger ones to be found in shallow parts of the marsh. This relationship of increased depth of water to turtle size and age continued through to sexual maturity. They concluded that by restricting their activity to shallow, near-shore water, the younger and smaller Painted Turtles may increase their foraging success as well as reduce the probability of running into adult turtle or fish predators. Reproduction and Growth In Michigan and the Great Lakes region, courtship and mating of the Painted Turtle may occur any time the animals are active (Harding 1997; Holman, personal observations in Michigan and Indiana), but they are most common in the spring. In Michigan I have seen male

2. Species Accounts

Midland Painted Turtles during April actively chasing both males and females of the same species in the open water of Colby Lake near Lansing. I suspect this activity relates to courtship or territoriality or both. When the two sexes finally do come together, the courting male swims backward in front of a female while vibrating his elongated front claws on the sides of her head and chin, a process sometimes called titillation. The female touches the male’s front legs with her own claws during this courtship. Finally the female sinks to the bottom of the pond or lake and lets the male mount her from above and clasp her shell with his claws. The introduction of male sperm into the female takes place when the male moves backward, bringing the vents together so that his penis may be inserted. In both Michigan and Indiana, I have seen Midland Painted Turtles encounter one another in the water, have a brief bout of mutual titillation, and then swim away. This activity tends to occur in the late summer or early fall. I have seen very small male Midland Painted Turtles in captivity attempt to court larger females of the same species with no success and other small males of the same species stroke the water with no other turtles present. In Michigan, females nest from late May into July (Harding and Holman 1997). The females usually look for open sunny sites near the water where there is moist sand or soil. They sometimes may be seen nesting in odd sites, such as in backyards or gardens or at the edge of golf courses. In rural areas, I have seen them nesting in the loose soil near mailboxes. The female usually deposits seven or eight (and sometimes as few as four or as many as twenty) eggs that are soft shelled and oval in shape. In Michigan, 15 to 30 percent of Midland Painted Turtles lay two clutches of eggs a year (Tinkle et al. 1981; Congdon and Tinkle 1982). After depositing the eggs, the female carefully covers up the nest. The eggs usually hatch in about seventy to eighty days in Michigan. Some hatchlings emerge and move away from the nest before winter, but many others overwinter in the nest, dispersing in the spring. The carapace of the hatchlings is normally about 2.54 cm (1 in.) in length. Chrysemys picta has temperature-dependent sex determination (TSD) by which cooler average nest temperatures (below about 27.5ºC or 81.5ºF) midway during incubation usually produce only male hatchlings.

Mostly females are produced at higher temperatures, although females may also be produced at very low temperatures near the minimum temperature for successful incubation (about 21ºC or 70ºF) (Ewert and Nelson 1991; Ernst and Lovich 2009). Growth in Painted Turtles depends on water and air temperature, the amount of rainfall, and availability of food; thus, growth rates may vary from locality to locality, season to season, and year to year or intervals of years. Gibbons (1967) studied the growth of Chrysemys picta marginata in three distinctive habitats in southwestern Michigan from 1964 to 1966. The Sherriff ’s Marsh habitat was composed of several hundred acres of grass and sedge and ten acres of open water. Wintergreen Lake, the second habitat, had about twenty acres of surface area and was very organically enriched. The third locality was a highly polluted stretch of the Kalamazoo River, where most of the Painted Turtles were taken from a mudflat with little aquatic vegetation. The turtles observed in Sherriff ’s Marsh were herbivorous, feeding on mainly aquatic vegetation. Turtles from Wintergreen Lake were omnivorous, feeding on both plant and animal matter. Turtles from the polluted Kalamazoo River were mainly carnivorous, feeding on invertebrates (midges made up their diet in June, and cladocerans were the most abundant prey in August). Painted Turtles from the Kalamazoo River had the greatest maximum size and rate of growth. Those from Sherriff ’s Marsh had a relatively slow rate of growth and a small maximum size. Turtles from Wintergreen Lake were intermediate between the other two populations in both size and growth rate, but they most closely approached the Kalamazoo River turtles in these characteristics. Frazer et al. (1991), in a separate study, found that the growth rates of Midland Painted Turtles in Sherriff ’s Marsh increased during the 1980s compared to those of the 1960s but that the survival rates of the 1980s group of turtles apparently declined. They suggested the higher growth rates in the 1980s group of Painted Turtles was possibly the result of warmer and drier weather during this interval. Diet Painted Turtles are omnivorous animals that eat an amazing variety of plants and animals. Ernst and Lovich

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(2009, 293) stated that “painted turtles are omnivorous generalists in the broadest sense; most species of plants and animals, living or dead, found in their habitat may be eaten as opportunity arises.” These authors then provide an incredibly long list of plants and animals that Painted Turtles eat. Small Painted Turtles are characteristically carnivorous but become more herbivorous as they grow. Relative to Michigan, Harding and Holman (1997, 42) stated that “painted turtles feed in water on a variety of foods, including aquatic plants, insects, snails, crayfish, tadpoles, small fish, and carrion.” Lagler (1943) reported on the frequency of occurrence of food items in 394 stomachs of Midland Painted Turtles in “natural waters” at various localities in Michigan. Percentage Food 58.9 Cryptogams (lower plants) 55.1 Insects 48.2 Phanerogams (higher plants) 35.5 Vegetable debris 15.7 Mollusks 15.5 Crustaceans 3.4 Leeches and “earthworms” 3.0 Spider and water mites 1.5 Carrion 1.5 Forage fishes 1.0 Game fishes 0.8 Fish remains 0.3 Frog remains A surface-skimming technique of procuring food used by Midland Painted Turtles is described as neustophagia by Belkin and Gans (1968). In this method of feeding, the turtle’s head is poked out of the water at about a 45-degree angle. The lower jaw is dropped so its cutting edge is even with the surface, and at the same time the throat is expanded. The head and neck are then slowly pulled back until the surface film is broken, causing the water to flow into the turtle’s throat. After a few seconds, when its throat becomes partly filled, the turtle closes its mouth. Doing this traps fine particulate matter, including tiny plants and animals that live on the surface of the water. Painted Turtles must swallow their food underwater, but I have seen them dash up on a bank to seize bits

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of carrion and carry it back to the water to swallow. Crawford Jackson once trained captive Painted Turtles to leave a shallow tank of water by way of a flat board to look around for pieces of preferred food in the vicinity of the far end of the board. When the turtles found the pieces of food, they would pick them up and carry them back across the board to the water to be swallowed. I have always been amazed how quickly captive Midland Painted Turtles learn to associate an approaching human with food. The response of the turtle, which often occurs just a few days after captivity, is to vigorously splash around while extending the head and neck toward the approaching food provider. Predation and Defense Ernst and Lovich (2009) list the nest predators of Painted Turtles, which include thirteen-lined ground squirrels, chipmunks, woodchucks, gray squirrels, skunks, badgers, foxes, raccoons, fish crows, gartersnakes, and humans. They emphasize that the raccoon is the major nest predator of this species. Additionally they report that rice rats, muskrats, mink, raccoons, snapping turtles, watersnakes, Cottonmouths, Racers, American Bullfrogs, large fish (such as bass and catfishes), and herons feed on the young. Adult Painted Turtles may be taken by alligators, raccoons, bald eagles, osprey, and redshouldered hawks. When closely approached by humans, Midland Painted Turtles beyond the juvenile stage immediately scramble off their basking sites and dive to the bottom of the pond, where they hide in vegetation or mud at the bottom. This is usually not for long, as they seem to be very nervous turtles “anxious to get about their business,” whether it be basking or foraging. If grasped, they usually attempt to get away by kicking and scratching while releasing large amounts of urine and sometimes vigorously biting. Hatchling and juvenile Painted Turtles are much less wary of humans than are older individuals. Hatchlings are usually found in vegetation in shallow water near the shore. When a hatchling is located in this setting, it can be merely picked up. Juveniles are somewhat more wary than hatchlings but still not as wary as older turtles. Sometimes they too may be easily picked up by hand in shallow water, and other times they bury themselves in the mud. When basking, juveniles often wait until

2. Species Accounts

the last second to dive into the water. Algae (Basicladia chelonum) sometimes grows on the shells of Painted Turtles in Michigan (Gibbons 1968b). This growth may camouflage these turtles when they are resting on the bottom. Interaction with Humans If I were to pick the Michigan turtle that has the best chance to survive this millennium and beyond, it would be the Painted Turtle. These animals appear to be able to digest almost any kind of food, have amazing tolerance to physical factors such as freezing and oxygen depletion, are tolerant of pollution, and are relatively prolific compared to other turtles. Harding (1997) pointed out that Painted Turtles are harmless to human interests and that they have considerable aesthetic value for many boaters and canoeists. He also noted that their consumption of mosquito larvae may be useful. Unfortunately, basking Painted Turtles in Michigan are sometimes shot for target practice by vandals with firearms. It is against the law to shoot any turtle in Michigan. Local die-offs of Painted Turtles sometimes occur in Michigan. It is important to find out whether this happens because of natural causes or whether it is induced by humans (Harding 1997). Knowing the reasons has very practical applications to humans, since any pollutant that can kill off a reptile as hardy as the Painted Turtle could very well be a threat to game species as well as people. A study of Dewart Lake in northern Indiana indicated that increased mortality in Painted Turtles was likely related to a great increase in shoreline development over the previous two decades and an accompanying great increase in the use of boats and personal watercraft during the previous decade (G. R. Smith et al. 2006). Behavioral Characteristics The behavioral characteristics of the Painted Turtle may be found in the sections “Habitat and Habits,” “Reproduction and Growth,” “Diet,” and “Predation and Defense” in this account. Population Health The Painted Turtle is not threatened or endangered in Michigan. It is the most common and widely distributed

turtle in the state and in the entire Great Lakes region as well. General Remarks Painted Turtles, because of their adaptability and abundance, are one of the most widely studied reptiles in North America. Important research has dealt with their anatomy, behavior, genetics, ecology (especially), paleontology, and physiology. Fortunately, some of the more recent studies of this species have been conducted without the sacrifice of the turtles.

Clemmys guttata (Schneider 1792) Spotted Turtle Identification The Spotted Turtle can usually be quickly identified by the round yellow spots on its smooth black or brownish black carapace. These spots vary in number and can be faded or absent in some individuals. Clemmys guttata is a small turtle whose adult carapace length ranges in Michigan from about 90 to 127 mm (3.5–5.0 in.). The plastron lacks a hinge and is usually yellow or orange with large black blotches on each epidermal scute. Occasionally, however, the plastron may be solid black. The head of this species is black and usually has at least a few spots on top. Irregular yellow or orange blotches usually occur on the sides of the head as well. Males typically have brown eyes, tan chins, and concave plastrons. Females typically have orange eyes and flat or convex plastrons. General Distribution The Spotted Turtle ranges from southeastern Maine southward along the eastern seaboard to northern Florida, and across the north westward to the Georgian Bay region of Ontario, Canada, through Pennsylvania, the Lower Peninsula of Michigan, Ohio, and Indiana, to extreme northeastern Illinois. Michigan Distribution The Spotted Turtle has not been recorded in the Upper Peninsula of Michigan nor, as far as I am aware, has it been reported from any Michigan islands. It has been recorded in roughly the bottom two-thirds of the Lower

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Peninsula, but the highest densities are historically associated with the southern and western portions of the LP. This turtle has not been reconfirmed in Kalkaska, Lake, Clinton, Ingham, Jackson, and Branch counties within the last twenty years. However, the species has not been systematically surveyed throughout Michigan and may occur in additional counties as well as those in which it has not been recently found (Lee 2000a). Geographic Variation No subspecies are currently recognized in Clemmys guttata, and no distinct populations of this turtle have been reported from Michigan.

FIG. 69. Spotted Turtle (Clemmys guttata) from Michigan. Photograph by James H. Harding.

Habitat and Habits Over their range, Spotted Turtles need clean, shallow, slow-moving aquatic habitats with mucky or muddy bottoms and emergent vegetation. The types of shallow wetlands they prefer include shallow ponds, wet meadows, tamarack swamps, bogs, fens, sedge meadows, wet prairies, shallow cattail marshes, sphagnum seepages, small woodland streams, and roadside ditches (Harding 1997; Ernst and Lovich 2009). M. M. Hensley showed me a site in Barry County in the spring of 1967 that he said was the most typical habitat for the species in southwestern Michigan. It consisted of a marsh draining into a shallow lake by means of a few very small streams. We saw several Spotted Turtles that day. All of them were walking slowly along the bottom of the smallest of

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these streams, all of which had just a trickle of water in them at the time. Ernst and Lovich (2009) reported that Spotted Turtles have a relatively short activity cycle compared to those of other North American turtles. Lovich (1988) compared the seasonal cycles of Spotted Turtles in Maryland, Pennyslvania, Ohio, and South Carolina. Activity levels measured by capture frequency were highest in the spring for all populations, and by my observations this is evidently true in Michigan as well. The activity levels in most states reached a peak in May, except in South Carolina, where they peaked in March. The activity levels of Spotted Turtles began to decline in June in all the states except South Carolina, which began to decline in April. The proportion of turtles captured between March and May were 74 percent in Maryland, 68 percent in Pennsylvania, and 93 percent in Ohio. In South Carolina, 50 percent of the captures during the year were in February and March (Lovich 1988). Spotted Turtles’ periods of activity and inactivity are closely associated with temperature. The turtles are most active during the cooler parts of the spring and summer season. A peak in this activity level is reached when the mean monthly air temperature is between 13.1 and 18.0ºC (55.6–64.4ºF) (mean 15.5ºC, or 59.9ºF). This peak occurs at least two months before the highest mean air temperature is reached. Activity declines when the monthly air temperature is between 17.8 and 22.3ºC (64.0–72.1ºF) (mean 20.3ºC, or 68.5ºF). The peaks of activity are closely associated with feeding activity. That these turtles are active at such cool temperatures probably relates to why they are infrequently seen in Michigan, at least by the casual observer. Most of the Spotted Turtle sightings I have experienced in Michigan were in April, which of course is only the very beginning of spring in this northern border state. In April they spend much of their time basking on muskrat houses or masses of grasses or sedges. Later in the season they hardly bask at all. As the habitat begins to dry up during the summer, these turtles retreat into the burrows of muskrats and other animals. Harding (1997) reported that they also dig into the mud or submerged root systems during these times. Summer dormancy occurs in Spotted Turtles when the water temperature reaches 32ºC (89.6ºF) (Ernst 1976).

2. Species Accounts

In the Great Lakes region, Spotted Turtles generally hibernate in shallow water situations from mid-October to late March (Harding 1997). They apparently use some of the shelters into which they retreated during times of drought and dormancy during the summer, such as shallow water with a muddy bottom or in muskrat lodges or burrows. Ernst (1982) reported that these sites are deep enough not to completely freeze but will thaw rapidly in the spring. These turtles become active when the water temperature is as low as 3ºC (37.4ºF). Such an adaptation allows the cold-tolerant Spotted Turtles to get a “head start” on some of the other turtles in the state. Spotted Turtles have homing ability, as demonstrated by Ernst (1968) in a Pennsylvania study. He collected twenty-five male and twenty-five female Clemmys guttata during the spring at one site and released them .31 km (.19 miles) upstream from where they were captured. Turtles that were recaptured within 27 m (88.6 ft.) of the original point of capture were considered to have homed, and this occured with eight females and six males. Moreover, four males and three females were recorded within 27 to 73 m (88.6–239.4 ft.) of the original capture site. Three turtles actually returned to within 1.5 m (4.9 ft.) of the original site of capture. No differences in homing ability were detected between the sexes. Reproduction and Growth Spotted Turtles begin to breed very near the time they emerge from winter dormancy in March or April (Harding 1997). A second mating period may also occur before hibernation in the fall. Breeding activity has been documented at a body temperature as low as 8ºC (46.4ºF). Male Spotted Turtles fight one another during the mating season, sometimes near the female but also at other times when males encounter other males by chance. The males bite each other and sometimes try to mount each other or turn the other over on his back. The winner finally drives the competitor away. Courtship takes place in shallow water and on the land nearby. During courtship, male Spotted Turtles usually chase the female while biting her legs, tail, and carapace. Ernst and Lovich (2009, 210) stated that “courtship involves frantic chases of a female by one or more males, covering 30–50 m, and lasting from 15 to 30 minutes.” Actual mating usually takes place in the water. The successful male will mount the female and

bite at her head and neck while holding the edge of her carapace with his claws. Finally, he will slide backward or sideward of her carapace and bend his tail under hers. This allows the vents to come in contact and his penis to be introduced for insemination. Copulation is reported to last from about fifteen minutes to more than an hour. The nesting process of Spotted Turtles in Pennsylvania has been described in detail by Ernst (1970b). Several holes may be dug before the true nest is made. At this point, the female orients toward the water and braces her front legs. She digs the nest with alternating strokes of her back feet. The digging generally takes 29 to 75 minutes, and she begins laying her eggs after the nest is completely excavated. The female stretches out her neck before each egg is to be laid and contracts it as each egg is pushed out. She uses her back feet to arrange the eggs in the nest. She starts to backfill the nest about five minutes after egg laying is completed. She fills the nest with soil and grass by the use of her feet and smooths the top with her plastron before returning to the water. The whole process takes 45 to 120 minutes. Hatchlings have a bluish black carapace, usually with a single spot on each scute, except for the cervical scute (the first scute behind the neck), which has none. However, some hatchlings have no carapace spots. The head of hatchlings is spotted and there may be spots on the neck. The carapace length ranges from 28.0 to 31.3 mm (1.10–1.23 in.). The hatchlings’ tails are proportionally longer than those of the adults. Hatchlings have a sharp protuberance on the snout called the caruncle, or “egg tooth,” which may help in tearing the eggshell. It drops off about a week after the turtles have hatched (Ernst 1970b). Growth rates of eleven Rhode Island Spotted Turtles were studied by Graham (1970). Graham found that the mean plastron lengths for each age class were: Age class Hatchlings One year Two years Three years Four years Five years Six years Seven years

Plastron length 24.73 mm (.97 in.) 35.36 mm (1.39 in.) 42.57 mm (1.68 in.) 48.80 mm (1.92 in.) 54.89 mm (2.16 in.) 59.82 mm (2.36 in.) 67.47 mm (2.66 in.) 72.92 mm (2.87 in.)

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The Amphibians and Reptiles of Michigan

The estimated growth rate of Pennsylvania Spotted Turtles was just slightly greater than those of the Rhode Island Spotted Turtles (Ernst 1975). Harding and Holman (1997) reported that Michigan Spotted Turtles had an adult carapace length of 90 to 127 mm (3.54–5.0 in.). Diet Harding and Holman (1997) stated that Spotted Turtles eat a variety of small animals and plants, such as insects, snails, worms, slugs, crayfish, tadpoles, duckweed, algae, and fruit. Relative to the Great Lakes region, Harding (1997) reported that feeding in Spotted Turtles takes place almost entirely underwater but that food may be obtained on land and carried into the water for consumption, as with the Painted Turtle. This species is omnivorous but prefers animal food and will consume carrion from time to time. Their favorite prey includes worms, mollusks, small crayfish, spiders, adult and larval insects, and tadpoles. Plants eaten include algae, tender leaves, and water lily seeds. Ruthven et al. (1928) stated that the food of the Spotted Turtle consists largely of dead fish and the larvae of aquatic insects. Referring to Indiana turtles, Minton (2001, 180) reported that “Spotted Turtles feed both on land and in the water.” I assume this statement does not mean the food is actually swallowed on land, but it is possible that individuals in some populations actually do swallow certain items on land. Predation and Defense In Michigan and the Great Lakes region, Spotted Turtle eggs are eaten by such mammals as skunks and raccoons; these same animals also attack and eat the vulnerable hatchlings and juveniles. Adults can be maimed by mammalian predators when they are foraging on land or nesting. When these turtles lie dormant in muskrat abodes, they are occasionally gnawed on by these rodents. Lovich (1989) reported that 31 percent of the Spotted Turtles from an Ohio site, Cedar Bog, had predator-related injuries such as missing limbs and tail and shell damage. In northern Indiana, Grant (1936) found Clemmys guttata whose shells had been damaged by rodents and others that had been killed or mutilated by unidentified predators. Spotted Turtles do not tend to bite when attacked (except by other Spotted Turtles during the breeding season) and thus are rather defenseless. An interesting

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passive defense has been suggested by Ross and Lovich (1992) from observations that the spotted pattern of the carapace may imitate duckweed, which can be seasonally common in the habitat of this turtle. Masses of duckweed characteristically spread over the surface of open areas of ponds and marshes in Michigan during the summer. When Spotted Turtles are startled while basking, they dive into the water and burrow into the sediments on the bottom. Interaction with Humans Boggy habitats in Michigan and the southern Great Lakes region were much more common in the past. During the last few decades, more and more of these sites have been drained for cultivation, urban spread, and other human uses. Harding (1997, 183) stated that “preserving viable populations of the species [Spotted Turtle] will require identifying and then protecting the core wetland habitats, along with the adjacent upland nesting sites and dispersal routes between colonies.” The bad news is that Spotted Turtles are not safe even where their habitats are protected because these small, pretty turtles are valued by reptile hobbyists throughout the world. Thus, collectors have vastly reduced or eliminated populations throughout the range of this species (Harding 1997). Actually, these turtles are very nervous when confined, and I would imagine that many of them do not do well in captivity. Behavioral Characteristics For Spotted Turtle behavioral characteristics, see the sections “Habitat and Habits,” “Reproduction and Growth,” and “Predation and Defense” in this account. Population Health The Spotted Turtle in Michigan is listed as Threatened and is protected under the state’s Endangered Species Act. It is against the law to take this species from the wild except when authorized to do so under an endangered species permit from the MDNR. The term “take” means “to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or attempt to engage in any such conduct” (MDNR, n.d., Spotted Turtle). General Remarks The Michigan Natural Features Inventory (cited in

2. Species Accounts

previous sections) has come up with a set of research recommendations needed to help protect the Spotted Turtle in Michigan. These are: 1. An assessment of the species’ current distribution and status throughout the state. 2. Identification of nesting and wintering areas at these sites. 3. Additional general life history and ecology information specific to Spotted Turtles in Michigan (e.g., movement and dispersal distances, home range, habitat use, reproductive success, long-term survivorship, potential carrying capacity). 4. Investigation of the impacts of various land uses and management activities on Spotted Turtle populations and habitat. 5. Investigation of the genetic diversity of extant populations. 6. Documentation and quantification of the impact of illegal collecting of Spotted Turtles in Michigan. 7. Investigation and development of effective strategies for ensuring the long-term viability of Spotted Turtles.

Emydoidea blandingii (Holbrook 1838) Blanding’s Turtle Identification Blanding’s Turtle is a mediumsized to fairly large turtle with a long, domelike shell. The carapace is black with a variable number of small yellow or brown spots and streaks. The best field mark for this turtle is the bright, solid yellow chin and throat. The late great herpetologist Walter Auffenberg said the best way to tell a Blanding’s Turtle from any other is by its silly grin (as looked at from the front of the head, caused by the notch in its upper jaw). The rest of the head is dark with brown or yellow spots. The plastron has a large dark blotch at the outer edge of each of the epidermal scutes. A hinge line is located between the pectoral and abdominal scutes at about the middle of the plastron. The hinge varies in flexibility but can usually at least partially close the shell of this turtle (though in some specimens it may not close the shell at all). The adult

carapace length of Blanding’s Turtle in Michigan ranges from 152 to 274 mm (5.98–10.51 in.). General Distribution The continuous range of this species is from eastern Ontario and adjacent Quebec, Canada, west to central Minnesota, southwestward to central Nebraska, and east to central Illinois and extreme northwest Pennsylvania. Isolated populations occur in southwestern New York, eastern New England, and Nova Scotia, Canada (Minton 2001).

Fig. 70. Blanding’s Turtle (Emydoidea blandingii) from Ingham County, Michigan. Photograph by the author.

Michigan Distribution In Michigan, Emydoidea blandingii is quite uncommon in the Upper Peninsula. In the western part of the UP it has apparently not been recorded from Baraga, Houghton, Keweenaw, Gogebic, and Ontonagon counties. In the eastern part of the UP it has not to date been recorded from Alger or Luce counties. As far as I can ascertain, there are no records of this species from any Michigan islands. Blanding’s Turtle is widespread across the Lower Peninsula of Michigan and is probably present in all counties with suitable habitat, although records are deficient for the counties surrounding Grand Traverse Bay. Geographic Variation Apparently no distinct populations of this species exist in Michigan. No subspecies are recognized in Emydoidea blandingii (Crother 2008).

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The Amphibians and Reptiles of Michigan

Habitat and Habits Typical habitats for Blanding’s Turtle in Michigan are exemplified by two sites in southwestern Michigan. These are Sherriff ’s Marsh, which is composed of several hundred acres of grass-sedge vegetation and ten acres of open water, and Wintergreen Lake, which has about twenty acres of surface area and is very organically enriched (see Gibbons 1967). Harding (1997, 203–4) stated, relative to the Great Lakes region, that “for most of the year Blanding’s Turtles live in and around shallow, weedy waters such as ponds, marshes, swamps, and lake inlets and coves. They are sometimes found in rivers but concentrate their activities in backwaters, embayments, and sloughs, and are only transient in portions of streams with more than a sluggish current.” A rough calculation of the population size of Blanding’s Turtles over 100 mm (3.94 in.) in plastron length from Sherriff ’s Marsh in southwestern Michigan indicated 561 individuals, providing that none of them emigrated from or immigrated to the marsh (Gibbons 1968c). I have seen Blanding’s Turtles basking, usually in the company of Midland Painted Turtles, as early as late March and as late as early November in the Lansing area of Michigan. I saw a large Emydoidea blandingii basking among a large congregation of Midland Painted Turtles on logs in a swamp near Ovid Lake in Clinton County, Michigan, on March 8, 2000, and a large adult Emydoidea blandingii was basking on a tree branch in a roadside ditch 1.5 miles south of Laingsburg in Shiawassee County, Michigan, on November 5, 2001. The air temperature at the time was 50ºF. One individual was observed crossing a road in southwestern Kalkaska County in early October, when the air temperature was 45ºF. During the summer months in Michigan, Blanding’s Turtles continue to bask, but they are not as frequently seen as in the early spring. Harding (1997) pointed out that during the summer heat Blanding’s Turtles may restrict their activities to early morning and early evening situations and that they may even become nocturnal in their activities. Harding noted that with the aid of a flashlight he has watched Blanding’s Turtles stalk crayfish at night on the bottom of a constructed pond in the Lansing area (pers. comm.). As the summer progresses, the shallow-water habitats of Emydoidea blandingii begin to dry out, which leads some of these animals to migrate to other aquatic

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situations. Some individuals instead burrow under roots, mud, plant debris, or other sediments until conditions improve. Blanding’s Turtles usually hibernate underwater, although they occasionally hibernate in sediments near water. In the Great Lakes region, they hibernate from late October or early November until late March or early April. Harding (1997) reported that they are cold tolerant and frequently seen moving under the ice. In northern Indiana, Evermann and Clark (1916) saw them swimming beneath the ice in November. Blanding’s Turtles in the Lansing area of Michigan usually emerge from hibernation in early April. On April 7, 1998, I observed Blanding’s Turtles moving from a roadside ditch down to an extensive marsh near Dansville in Ingham County. Unfortunately they had to cross a road to get to the marsh. When I arrived at the site where the turtles were active, I found seven large individuals had been recently run over and were dead. A woman passing by helped me remove at least four live large adults from the road and put them in the marsh, and we watched two more scramble safely down the bank toward the marsh. All of the individuals we saw had various quantities of mud caked on their shells and must have recently emerged from their winter shelters in the ditch. Reproduction and Growth In the Great Lakes region, mating can occur from April to November, but usually it occurs in the spring (Harding 1997). Baker and Gillingham (1983) observed courtship and mating in Michigan Blanding’s Turtles under controlled but semi-natural conditions in water between April 20 to May 28 at water temperatures ranging from 7 to 21ºC (44.6–69.8ºF). The authors recognized eight male behaviors involved in the courtship process: 1. The chase involves the pursuit of the female. Often the male is in contact with the posterior part of the female during this stage. 2. The mount involves the male climbing onto the back of the female and grabbing her carapace with his claws. 3. Gulping consists of the male sucking water into his mouth and blowing it out his nostrils or mouth over the snout of the female. 4. Chinning involves the male putting his chin over the snout of the female and exerting downward and inward pressure on her snout.

2. Species Accounts

5. Chin rubbing consists of a sideways movement of the male’s head over the female’s snout. 6. Swaying consists of horizontal movements of the male with his neck extended and head bent downward at a sharp angle. No contact is made with the female during this movement. 7. Violent swaying consists of rapid horizontal head swinging positioned in such a way that the head can move under the plastron of the female. 8. The snorkel occurs at intervals between the various behaviors described; at this time the male is motionless and only slowly raises his head up to the water surface to breathe. To add further detail to some of these behaviors, the authors noted that chinning could last for up to seventy minutes, but the mean time was four minutes. Chin rubbing usually followed a snorkel by the male or a try at breathing by the females. If the mounted female moved forward, the male would stop chinning and would go into gulping bouts, each bout consisting of sixteen to thirtyseven pulsations with a mean of twenty-two. Usually swaying followed gulping, and if the female pulled in her head during this stage, the male would start chinning again. If she remained motionless, violent swaying by the male ensued, especially if she pulled all her appendages into her shell. Mating finally occurred when the female extended her tail following the swaying behavior of the male. The male then would put his tail beneath hers and insert his penis. At this point the male would release his grip and tilt his body backward. Violent swaying by the male was associated with his dismounting of the female. Mating lasted 16.5 to 29.3 minutes with a mean of 23.0 minutes. Humans may be amazed by such a complicated courtship procedure in such an ancient and shellencumbered animal. Congdon et al. (1983) studied the nesting ecology of Blanding’s Turtles at the E. S. George Reserve in southeastern Michigan (Livingston County) from 1976 through 1981. They found the time of the nesting season was determined by April temperatures and that the beginning of the season ranged from May 23 to June 9 and lasted sixteen to thirty days (mean twenty-three days). Nesting activity occurred almost entirely in the evening, with the average completion time happening at 9:19 p.m. Most of the females returned to the same

general nesting area each year. The nesting areas were usually not adjacent to the resident marsh of the female. Nests were located at a mean distance of 135 m (442.8 ft.) from the nearest aquatic habitat. Predation led to 82 percent of nest mortality, and most predation (84 percent) occurred within the first five days after the nest was completed; 47 percent occurred within the first twenty-four hours. In the nests that survived predation, an average of 1.2 eggs per nest did not develop, and just 22 percent of the clutches produced hatchlings. (It’s sobering then to think that the hatchlings will also face heavy predation.) The average time from egg laying to the emergence of hatchlings was eighty-four days during a period from mid-August through early October. Forty-five percent of the hatchlings emerged within one day and 55 percent took more than one day to emerge. Female Blanding’s Turtles mature at a plastral length of 160 to 162 mm (6.3–6.4 in.). As few as 23 percent and as many as 48 percent of the females in the populations studied reproduced in a given year, and those that did reproduce laid only one clutch of eggs. The clutch size ranged from three to fifteen eggs with an average of ten eggs per nest. All of this data leads to the conclusion that the recruitment into the adult Blanding’s Turtle population each year must be very, very low. Harding (1997) reported that in the Great Lakes region nests are dug in open, sunny areas with welldrained sandy or loamy soils. Many types of nesting sites are used, including lawns, gardens, and plowed fields. The nest itself is dug by alternating strokes of the hind feet of the females. The eggshells of Blanding’s Turtles are at first very rigid, but then they absorb water and become softer as they incubate in the nests. Blanding’s Turtles have temperature-dependent sex determination (TSD). Eggs incubated at 25ºC (77ºF) or lower will produce all males. Those incubated at 30ºC (86ºF) or above will produce all females. Blanding’s Turtles grow to sexual maturity within about fourteen to twenty years. Blanding’s Turtle hatchlings seldom overwinter in the nest (Packard et al. 2000). The reason is that when hatchlings overwinter in the frozen soil of the nest, ice crystals penetrate the integument. This usually causes body fluids to freeze at temperatures below the limits of tolerance of the tiny turtles.

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Congdon and van Loben Sels (1991) studied growth and body size in Blanding’s Turtles at the E. S. George Reserve from 1975 to 1988. They found that the average body size of both males and females were similar but that the plastra were of different shapes—flatter in females and more concave in males. The average size of females of a mean maximum age of forty-seven years was not different from a younger group with a mean age of just twenty-one years. Clutch sizes in 280 nests ranged from 3 to 19 eggs with a mean of 10.2 eggs. The clutch size, and to a lesser extent the egg size, was related to the body size of the females, but it did not correlate with the age of the females. The plastron of hatchlings averaged 31.0 mm (1.22 in.) in length and the carapaces averaged 35.3 (1.39 in.) in length. These authors found that differences in juvenile growth rates and sexual maturity appeared to be a major cause in determining the body size of the adult turtles as well as the number of eggs in their clutches. Diet Lagler (1943) studied the food contents of fifty-one stomachs and forty-one colons of sixty-six Blanding’s Turtles from a variety of “natural” aquatic habitats in Michigan. He found that crayfish made up about half of the food of these Blanding’s Turtles. Another fourth of their food consisted of insects, and the final fourth consisted of miscellaneous invertebrates and plant material. The percentage of food in the stomachs of these turtles was: Food Percentage Crustaceans 74.5 Insects 54.9 Plant debris 39.2 Higher plants 31.4 Lower plants 21.6 Mollusks 17.6 Unidentified fish remains 7.8 Carrion 5.9 Forage fishes 5.9 “Game fishes” 5.9 Leeches 3.9 Bird remains 2.0 In Indiana, Minton (2001) watched Blanding’s Turtles feeding on snails and commented that they

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swallow a good deal of aquatic vegetation in the process. Blanding’s Turtles have highly developed gape-and-suck feeding behavior, expanding their very long necks and at the same time opening their mouths to suck in prey from the size of small crayfish to insects and snails. Predation and Defense Without a doubt, in Michigan raccoons are the top nest predators of Blanding’s Turtles and perhaps of the hatchlings as well. Other important nest predators are foxes and skunks. Being run over by cars and trucks is probably the major cause of mortality in the adults. Kofron and Schreiber (1985) found that in Missouri, injuries were distributed evenly among adult males, females, and subadults. Of the Blanding’s Turtles they collected, 31 percent had missing body parts or other injuries. Eleven had damaged shells, thirteen had foot injuries, and five had part of a tail missing. Blanding’s Turtles seldom, if ever, bite when picked up by humans or disturbed by other creatures. The usual defense mechanism employed is to pull in the head, limbs, and tail and close up the shell (to the extent that the weak plastral hinge will allow) and then play the sitand-wait game. Tragically, when cars pass near them on the road, they employ this strategy, only to be smashed by the next car or truck that comes along. Relative to defense mechanisms in their aquatic habitats, I would guess the small light spots on their carapaces help conceal them in duckweed patches, as has been suggested for Spotted Turtles. With reference to Indiana, Minton (2001, 183) stated that “this is a phlegmatic, docile turtle that retracts its head and limbs when captured and rarely tries to bite. It is vulnerable to both accidental and wanton destruction. I once saw four large ones that had been killed by gunfire in a shallow ditch.” I find such human behavior reprehensible. I suspect that some or all of the seven large Blanding’s Turtles I saw freshly dead on the road in Michigan had been purposely run over. Each one of those seven dead turtles was probably much older than the person who ran them over, who perhaps did it for fun. Interaction with Humans Unlike Spotted Turtles, Blanding’s Turtles have not been highly valued in the pet trade, probably because they are larger, active, and require a lot of space. The

2. Species Accounts

major negative impact that humans have on Emydoidea blandingii is habitat degradation and loss (Van Dam 1993) and destruction on roads. Specific sources of habitat damage or loss include inundation of wetlands, river channelization, water impoundments, agricultural modification of sloughs, pond herbicides and other pesticide use, and human development in upland areas (Kofron and Schreiber 1985). The fragmentation of Blanding’s Turtle habitat can pose a threat to these species, as nest predation, particularly by raccoons, skunks, and opossums, increases near the edges of these fragmented areas (Temple 1987). The tendency of nestseeking females to wander long distances from wetlands can bring them into peril while crossing roads. Behavioral Characteristics For the behavioral characteristics of Blanding’s Turtles, see the sections “Habitat and Habits,” “Reproduction and Growth,” and “Predation and Defense” in this account. Population Health Blanding’s Turtles are listed as a Species of Special Concern in Michigan, and state regulations on the taking of reptiles and amphibians note that it is unlawful to take Blanding’s Turtles from the wild except as authorized under a permit from the director of the MDNR. This regulation is enforced by the MDNR Fisheries Division. Some research projects that are needed to ensure the future health of Emydoidea blandingii in the state were published by the Michigan Natural Features Inventory (Lee 1999): 1. Identification of nesting and wintering sites as well as healthy populations. 2. Long-term studies that keep track of population trends throughout the state. 3. Gathering of information on the amount of habitat needed to sustain populations. 4. Obtaining information on overland migration and population recruitment. 5. Developing and implementing effective ways to educate the public about the status of this species and its needs.

General Remarks Most of the Michigan Blanding’s Turtles you will see in the field will be large adults. I have never come across a hatchling Blanding’s Turtle in the wild in Indiana or Illinois nor during my thirty-seven years of turtle watching in Michigan. Part of the reason, I am sure, is that hatchling and juvenile Emydoidea blandingii spend most of their time hiding in aquatic vegetation in shallow water and do not bask much, at least not out in the open. But the other part of the equation is that the mortality of eggs, hatchlings, and juveniles is very high. Once this turtle reaches a large adult size, not many predators eat them. Moreover, they are very long lived. Lee (1999, 2) summarized the conservation and management challenges posed by Blanding’s Turtles, stating that “Blanding’s Turtles are characterized by delayed sexual maturity, small clutch size, low reproductive success, high adult survival rates, and long adult lives. Given these life history traits, this species requires high annual survivorship of adults and juveniles to maintain stable populations.” A Blanding’s Turtle population at the E. S. George Reserve in southeastern Michigan had to have a yearly adult and juvenile survivorship of at least 93 percent and 72 percent, respectively, to maintain population stability (Congdon et al. 1993).

Glyptemys insculpta (LeConte 1830) Wood Turtle NOTE: Glyptemys insculpta was long known as Clemmys insculpta. The name was changed on the basis of fossil, morphological, and molecular evidence and was officially recognized by Crother et al. (2003). The common name for the genus Glyptemys is now “Sculptured Turtles” (Crother 2008). Only one other species, Glyptemys muhlenbergii (Schoepff 1801), the Bog Turtle, an endangered species of the eastern United States, occurs in the genus Glyptemys. It too was formerly in the genus Clemmys. Identification The Wood Turtle is a medium to fairly large-sized turtle that may be immediately distinguished by its keeled and heavily sculptured carapace that makes the animal look

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The Amphibians and Reptiles of Michigan

as if it were carved from wood. Each of the epidermal scutes on the shell of this turtle has well-defined growth lines (annuli) that are crossed by ridges that radiate out from the initial growth center of the scute. The color of the carapace is typically brown or grayish brown, sometimes with yellow raylike lines on the vertebral and pleural scutes. The plastron is yellow with a distinct black blotch at the rear outer corner of each epidermal scute. The back end of the plastron has a V-shaped notch where the tail exits. The head of the Wood Turtle is black, as are the upper parts of the neck, legs, and tail. The underside of the neck and the inner parts of the legs and tail are yellow or orange. The adult carapace length in the Great Lakes region ranges from 160 to 250 mm (6.3–9.8 in.) (Harding 1997). Adult males have concave plastra and longer, thicker tails than females, which have flatter plastra and narrower tails.

Keweenaw counties. It is not known from any of the Michigan islands. It occurs roughly in the northern twothirds of the Lower Peninsula but has not been recorded from the northwestern chain of counties bordering Lake Michigan. These counties include Leelanau, Antrim, Charlevoix, and Emmet. Wood Turtles also have not been recorded in the thumb area of Michigan nor in the counties bordering the southern and eastern portions of Saginaw Bay. Allegan County in southwestern Michigan has one isolated record; occasional reports of specimens in southern Michigan are likely based on introduced animals.

General Distribution The Wood Turtle occurs from Nova Scotia and New Brunswick, Canada, south to at least Rockingham County, Virginia, and west through southern Quebec and southern Ontario, Canada, and New York to northern Michigan, Wisconsin, Eastern Minnesota, and northeastern Iowa (Ernst and Lovich 2009).

Habitat and Habits In general, Wood Turtles are always found associated with aquatic situations, but the degree of this association varies seasonally and geographically. Wood Turtles in Michigan are usually found in or near rivers and streams. In fact, during an intensive study of this species from 1969 to 1978 in Michigan, no Wood Turtle specimens were taken more than 152 m (498.6 ft.) from water (Harding and Bloomer 1979). These aquatic tendencies are shared with Wood Turtles in Wisconsin, which, like the Michigan Glyptemys insculpta, are very aquatic and

Michigan Distribution The Wood Turtle has been recorded from every county in the Upper Peninsula with the exception of Alger and

Geographic Variation No distinct populations of Wood Turtles have been reported from Michigan, and no subspecies have been described.

FIG. 71. Wood Turtle (Glyptemys insculpta) from Clare County, Michigan. Photograph by James H. Harding.

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2. Species Accounts

prefer the moving waters of rivers and streams and their shoreline habitats (Harding 1991; Vogt 1981). In the eastern part of the Wood Turtle’s range, they are mainly terrestrial in the summer, but they enter streams every few days (Ernst and Lovich 2009). Basking is a highly developed activity in Glyptemys insculpta in Michigan. The turtles bask especially in the late morning and late afternoon on sunny days (Harding and Bloomer 1979). When paddling down a river in northwestern Michigan, I typically would see a basking Wood Turtle about every mile or so, usually in a small patted down flat area exposed to the sun but partially hidden by the brushy river bank. It seems this population has been reduced in recent years, possibly by collectors seeking these turtles for pets. Turtles unaccustomed to humans can appear quite tame. Years ago, on a stream in the Upper Peninsula, I saw a large female basking on a log very near the shore. I reached down and picked her up, and she kicked wildly, but I was very surprised that she had not plopped into the water earlier. Harding (Harding and Bloomer 1979) found that Wood Turtles sunning on logs in the UP were more wary; he stated that “specimens which choose emergent logs over water as basking sites were more conspicuous; when approached by land or water they would usually drop off and dive to the bottom, then scuttle along the shoreline or head directly to deeper water in the middle of the stream.” Holman and Harding (1977) noted that Wood Turtles basking on land are inconspicuous and that they often bury themselves in shallow pits that conceal the outline of their shells. In addition, whenever they leave the water, Wood Turtles almost always throw sand and dirt over their shells with an alternating flipping motion of the front feet. Some Michigan Wood Turtles show amazing site tenacity. A female that was marked on July 2, 1971, was recaptured in May 1972 on the same log as in 1971, and in May 1974, she was captured again on a bank next to the same log (Harding and Bloomer 1979). The homing ability of Wood Turtles in Michigan is well developed (Harding and Bloomer 1979). A female that was marked on June 22, 1971, was released about 8 km (4.96 miles) downstream from the place where she was caught. On August 11 the animal was found at the first capture point. If most of her travel was by water, she had covered the distance swimming against the current of the stream. A female missing a right front leg was

marked on June 23, 1971, and placed 1.6 km (.99 mile) downstream. In two days this individual had returned to the point of capture. This three-legged animal was again placed 1.6 km downstream and was back in four days. When displaced about 3.2 km (1.98 miles) downstream, she was not retaken that year, but five years later on June 15 she was again found at the original place of capture. One of the most curious habits of Wood Turtles is called “worm stomping” (Zeiller 1969; Harding and Bloomer 1979; Kaufmann 1986, 1989; Kaufmann et al. 1989). Wood Turtles perform behaviors related to feeding, mating, and other purposes that involve rhythmic alternating movements of the front and hind feet. The first reference to worm stomping in Wood Turtles was made in 1969 by Donald Zieller, a devoted turtle enthusiast who reported that he and his family watched a captive Wood Turtle catching worms in an area where the grass was fairly short. The turtle first used one leg to raise his body, and then he let it come down “with a thump.” The turtle repeated the procedure fifteen or so times and then switched to the other leg, again thumping about fifteen times. After these thirty or so thumps, a worm came up from the ground and was eaten by the Wood Turtle. The family watched while the turtle repeated the process and ate eight worms in twenty minutes. Since then this behavior has been observed in New Jersey, Pennsylvania, Michigan, and Wisconsin, but it has been studied in the wild only at J. H. Kaufmann’s study area in Pennsylvania, where several herpetologists (James Harding, John Kaufmann, and Kevin Brewster) have worked on the problem. There has been some question as to whether it is the turtle’s foot motion or the banging of the plastron on the ground that is causing the worms to come up. Kaufmann et al. (1989) stated that the plastron thumping adds to the effectiveness of the stomping in producing vibrations in the soil and could be more important than the stomping itself. Questions have been raised about worm stomping in Wood Turtles, but three sets of evidence indicate not only that the singular act of stomping can be effective but also how this behavior could have evolved (Kaufmann et al. 1989). 1. Gulls and plovers are able to cause worms to come up to the ground surface by foot movements alone. Gulls tramp up and down

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with alternate feet, and plovers simply extend a foot and vibrate it against the ground. 2. Kaufmann repeatedly caused worms to come to the surface by mimicking the rhythm and force of the front feet of the turtles with only two fingers. 3. Once, Kaufmann observed a worm surface and crawl toward a Wood Turtle that was walking nearby. The turtle was neither stomping its feet nor thumping its plastron on the ground. The worm was spotted and eaten by the turtle. Apparently, worms near the surface may emerge due to slight vibrations, sometimes even those caused by a walking Wood Turtle. Thus, any increase in force from that of just walking would increase the range and effectiveness of this stimulus on a favorite prey item, and plastral thumping resulting from foot stomping would magnify this. Wood Turtles typically hibernate under flowing water, but data on their hibernation in Michigan is limited (Harding and Bloomer 1979). No activity of these turtles has been recorded after mid-October, and in some years their active period was over by late September. Bloomer (1978) discovered that New Jersey Wood Turtles hibernated in beaver and muskrat burrows and also in the bottom mud of streams, ditches, and beaver ponds. He found that the turtles often congregated in large numbers, and he recorded groups of from five to seventy. Some hibernating groups of these turtles were not well concealed and were discovered in a dormant state, shell against shell on the bottom of a waterway under the ice. Bloomer believed this species is a social hibernator in New Jersey and that this congregating behavior does not reflect a lack of hibernating sites. Michigan Wood Turtles are not noticeably active until the middle of May. One male was spotted in late May emerging from between tree roots in an Upper Peninsula stream bank about two feet above the water. The carapace of this individual was caked with mud, and it was likely that this tree root system could have been a hibernating site. Other Wood Turtles have been found inside muskrat burrows and stream-bank root systems in the Upper Peninsula of Michigan in May, but Harding and Bloomer (1979) were not sure these sites represented hibernacula.

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Upper Peninsula Wood Turtles rarely associate with other turtles except in the spring, when they share their nesting sites with Painted Turtles and Snapping Turtles. In the Lower Peninsula, they may share basking sites with Northern Map Turtles (Graptemys geographica). In New Jersey, Glyptemys insculpta shares its habitat with Bog Turtles, Spotted Turtles, Painted Turtles, Snapping Turtles, and Eastern Box Turtles. Reproduction and Growth I have synthesized data on the Wood Turtle’s reproduction and growth mainly from Harding and Bloomer (1979) and added some of my own observations. Wood Turtles can mate at any time during their activity cycle, but mating occurs with the greatest frequency in the spring from April to June and in the fall from September to November. In Michigan, Wood Turtles mating in the wild were observed eight times: four times in the last half of June, one time in August, and three times in early September. It was suggested that these two mating seasons might reflect either hormonal changes in these turtles or that Glyptemys insculpta males and females congregate in the spring and fall. Mating usually takes place in the water, a typical site being the sloping margin of a stream or pond. Preliminary courtship behavior may occur on land but actual copulation on land is rare. Most courtship occurs in the late afternoon. Males usually start the courtship process, but three instances of New Jersey females initiating courtship have been observed. Fisher (1945) also reported such an occurrence. Both male and female Wood Turtles may mate more than once per season. Courtship usually begins in or near the water, where the male approaches the female and noses her shell and exposed body parts. A receptive female may evince the same behavior toward the male. The two sexes then face each other, assuming a nose-to-nose position, and bob and jerk their heads at each other. Sometimes they may swing their heads in a side-to-side motion. This part of the courtship can last more than an hour. If the female is reluctant to take part in courtship, the male may bite at her shell and try to chase her into the water. The male mounts the female in a short rush and grasps her carapace with his claws, biting continually at her head and front legs to keep her from escaping. Once the female settles down, the male attempts copulation by

2. Species Accounts

curling his tail so as to bring their vent areas in contact, probing with his penis until it can be inserted. In deep water it may be hard for the female to get a breath of air, and drowned females have been found in the wild. Wood Turtles may copulate for up to two hours. As copulation nears an end, the female will increase her attempts to escape and sometimes bite at the male’s head. Finally the male will release the female. Nesting in Wood Turtles in Michigan takes place mainly in June, with the earliest and latest dates being June 12 and June 29, respectively (Harding and Bloomer 1979). Nesting occurs in the afternoon and evening hours. Michigan females delayed nesting if the midJune weather was rainy and cold, but the arrival of the first sunny afternoon would cause a flurry of nesting activity, even with temperatures as low as 15.6ºC (60ºF). Requirements for nesting sites in the wild include exposure to direct sunlight and a substrate of sand or soil that holds moisture but is well drained, not likely to flood, and free of rocks and thick vegetation. In Harding’s study area in northern Michigan, thick woodland vegetation limited nesting sites mainly to a few open, sandy places—usually high sand banks near rivers and streams. A description of a typical nesting sequence of northern Michigan Wood Turtles based on five complete and a large number of partial nesting sequences is condensed here from Harding and Bloomer (1979). At 6:00 p.m. a female G. insculpta left the water, flipped sand over her carapace with her front feet, and moved slowly up on the flattened sand at the top of a beach (an area of open sand with clumps of horsetail [Equisetum sp.]). Seemingly wandering in a random manner, she walked with her neck extended, stopping every few feet to raise her head and begin digging motions with her hind legs. The turtle continued this activity for more than an hour. By 9:30 p.m. the turtle had chosen a nest site and was digging steadily with alternate movements of her back feet, bracing her body with her front feet. The female formed the egg cavity by cupping a hind foot, lifting adherent balls of moist sand, and dropping them at the sides of the nest. The final egg cavity was globular with smooth sides. At 10:40 p.m. the Wood Turtle stopped digging and rested for a few minutes. Then she put a hind leg into the nest and at the same time pulled in her head and raised the back end of her carapace

as the first egg was laid. Her hind foot, with its claws turned inward, moved the egg to one side of the cavity. This process was repeated for each egg, the hind feet alternating to arrange the ten eggs in a tight cluster. At 11:00 p.m., after a brief rest, the turtle began filling the nest by scraping moist sand from the upper part of the nest and packing it tightly around the eggs. She then scraped sand from the piles around the nest and packed it down with the flattened part of her feet. When the filled-in portion of the nest became level with the ground, she changed positions and rocked the back part of her plastron over the nest to aid in the smoothing and packing. At 11:45 p.m. the female moved in a halting manner toward the water, her hind feet still scraping the surface of the sand as she moved away from her completed nest. At 11:55 p.m. she hesitated and then walked over the edge of the bank and slid back into the water. Harding and Bloomer (1979) also found that in Michigan the number of eggs per clutch varied from 5 to 18 (mean 10.3 eggs per clutch). Clutches of 13 to 14 are common. The eggs are oval, white, and easily dented. The eggs range from 32.5 mm (1.28 in.) to 37 mm (1.46 in.) in length with a mean of 34.0 mm (1.34 in.). Eggs collected in Michigan and hatched in the laboratory at “room temperatures” required from 47 to 65 days incubation time with an average of 58.9 days. These eggs were covered with moist sand collected at the wild nest sites and kept in covered plastic boxes. A natural nest with eggs hatching in it was found on September 4, 1975, in northern Michigan. One hatchling was in the nest and another was just emerging from the exit hole. Four others were located under plants and leaf litter. Seven empty eggshells were found in the nest. Some of the hatchlings had lost their egg tooth while others had not. No evidence has been found to indicate that Michigan Wood Turtles overwinter in the nest (Harding and Bloomer 1979). Wood Turtles do not have temperature-dependent sex determination (Bull et al. 1985; Ewert and Nelson 1991). Data from Michigan in Harding and Bloomer (1979) indicate that growth rings (annuli) are a reliable indicator of age in wild Wood Turtle specimens under about fifteen years old, but they suggested that these rings probably become increasingly less reliable as individuals advance in maturity. However, most

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specimens recaptured during the Michigan study had added exactly one ring per year. Despite difficulties in counting annuli in old specimens, an average age for Michigan Wood Turtles was determined. For fortyone adult males, the average age was 21.46 years, and for fifty adult females, the average age was 20.18 years. A Michigan female with a recapture history had the following increments in carapace length: June 25, 1971 September 9, 1971 August 1, 1976 June 14, 1977

127 mm (5.0 in.) 133 mm (5.24 in.) 166 mm (6.54 in.) 168 mm (6.61 in.)

It was determined that, conservatively, Wood Turtles in the northern Michigan population studied do not become sexually active until they are at least ten years old. The smallest Michigan G. insculpta observed in courtship activity was a female 158 mm (6.22 in.) long with twelve well-defined growth rings. The smallest courting male was 192 mm (7.56 in.) long. The smallest female found laying eggs had a carapace length of 185 mm (7.28 in.) and had nineteen growth rings. Diet Wood Turtles are omnivores that consume a wide variety of plant and animal foods. Glyptemys insculpta is able to swallow food both in and out of the water. In the water they feed on such items as algae, aquatic insects, terrestrial insects that fall into the water, mollusks, tadpoles, dead fish, and carrion. On land they eat such items as raspberries, strawberries, green leaves, grasses, and earthworms. Lagler (1943) reported the stomach contents of nine adult Wood Turtles from Michigan. These turtles had eaten: 1. Filamentous algae and willow leaves 2. Plant material (mostly algae) and insect remains, including three blackfly larvae 3. Filamentous algae, caddis fly larvae, and many small mollusks 4. Remains of a beetle, a tadpole (Rana), and a snail 5. Part of a bluegill and a mass of caddisflies and their houses 6. Insect larvae, a snail, and a leaf part 7. Insect larval remains and their houses and a leaf trace

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8. Earthworms, an insect, moss, willow leaves, grass, and vegetable debris 9. Trout remains, insects, and vegetable debris, including some algae Lagler concluded that the Wood Turtle is not a concern to fish management in the state. Predation and Defense Wood Turtles have many natural enemies. The eggs, hatchlings, and juveniles are subject to a high rate of predation. The most important egg predators are raccoons and skunks, at least in Michigan. In Harding’s heavily forested northern Michigan study area, female Wood Turtles are forced to congregate in limited areas of suitable nesting habitat, which allows raccoons to destroy up to 100 percent of the eggs in some years (Harding and Bloomer 1979). Other egg predators in the study area were ravens and coyotes. Predators of hatchling and juvenile Wood Turtles were said to be raccoons, feral cats and dogs, opossums, various birds, Snapping Turtles, and large fishes. Adult Wood Turtles in the northern Michigan study area were not immune from predators, as 9.7 percent of the specimens marked were missing at least one limb and more than 2 percent had lost two legs. A female found on a stream bank was bleeding from the stumps of both legs and raccoon tracks were found in the immediate vicinity. In recent years, evidence of raccoons killing adult Wood Turtles outright has been noted (Harding, unpublished data). When attacked, the defensive behavior of the Wood Turtle is to pull its head and limbs into the shell and fold the thick-scaled front legs over the head. Nevertheless, the legs are still vulnerable to attack by mammals with narrow noses such as raccoons, skunks, and opossums. It has also been suggested that leg-hold traps set for furbearing animals might be a cause of loss of legs in Wood Turtles. A newly captured Wood Turtle in Michigan passed unidentified roundworms in its feces. Moreover, a nesting female was pestered by many blood-sucking flies that bit her head and neck. Interaction with Humans Wood Turtle populations in Michigan have greatly suffered from human activities. This species has been in great demand by the pet trade and has been exploited

2. Species Accounts

in this way in Michigan for the last few decades. The fact that Wood Turtles congregate for hibernation and nesting make them vulnerable to mass collecting, and some commercial collectors have taken advantage of this, seriously depleting or even eliminating some populations. Harding (1997) pointed out that in the Great Lakes region, populations of Wood Turtles have significantly declined, even where suitable habitats remain. In some places they have been adversely affected by habitat fragmentation and pollution, and the building of roads near rivers and streams has led to many turtles being run over by cars and trucks. Fisheries management practices, such as the stabilization of sand banks and the digging of sand traps in streams may not only reduce preferred habitats for this species but eliminate nesting sites as well. Yet human activities such as opening up dense floodplain forests can potentially create new basking and feeding areas as well as nesting sites. Also, Wood Turtle populations are able to persist in areas where a moderate level of development has occurred along rivers and streams as long as the turtles and their nesting sites are not molested. One problem in Wood Turtle management is people picking up the turtles and transporting them (which in itself is illegal) to areas outside of their natural range. When these people get tired of their new “pets,” they often release them in places where they cannot survive for long. One Wood Turtle was found crawling around in a parking lot on the campus of Michigan State University, well out of its natural range.

Graptemys geographica (Lesueur 1817) Northern Map Turtle

Population Health The Wood Turtle is listed as a Species of Special Concern by the MDNR. They are protected by state regulations and may not be taken from the wild or possessed without a scientific collecting permit issued by the MDNR.

General Distribution Northern Map Turtles occur from southern Quebec, Canada, and northwestern Vermont west through the Great Lakes region into southern Wisconsin and Minnesota. They are also found west of the Appalachians as far as Kansas, northeastern Oklahoma, and Arkansas, and in Tennessee, northern Alabama, and northwestern Georgia. These turtles also occur in the Susquehanna River systems of Pennsylvania and Maryland and the Delaware River of Pennsylvania and New Jersey. An isolated population may exist in the Hudson River (Ernst and Lovich 2009).

General Remarks The probable ancestor of both the Wood Turtle and the Bog Turtle is Glyptemys valentinensis, a well-studied fossil turtle from the Middle Miocene that lived in what is now Nebraska about 13 million to 11.5 million years ago (Holman and Fritz 2001). Modern Wood Turtles first appeared in Nebraska in the late Miocene, about 5 million years ago. This record is based on a perfect shell that appears to be identical to the modern species.

Identification The Northern Map Turtle is a medium to large species that has a network of darkly bordered yellow or orange lines on its olive to grayish-brown carapace. Both the common and the scientific name for this turtle derive from these lines that may vaguely resemble the network of roads or rivers on a map. The carapace also has a prominent central keel. Yellow lines occur on the Map Turtle’s head and neck, and an oval yellow spot is located behind the eye. Note that the Northern Map Turtle has no red markings on its shell, legs, or other body parts, in contrast to the Painted Turtles and Sliders. The plastron is broad and flat and is usually a rather drab yellow color with no extra markings except on some juveniles and a few males. Northern Map Turtles have more obvious sexual size dimorphism (sexual size differences) than any other Michigan turtles, except for the Eastern Spiny Softshell. Male Map Turtles are distinctly smaller than the females, with a carapace length ranging from about 100 to 160 mm (3.9–6.3 in.). Females have a carapace length ranging from about 170 to 273 mm (6.7–10.7 in.) (Harding 1997). Moreover, females have wider heads, a rounder carapace, shorter front claws, and shorter tails than males do. Also, the crushing surfaces of the jaws of females are much broader than those of the males.

Michigan Distribution In the Upper Peninsula, Northern Map Turtles have been recorded from only two counties: Dickenson in the

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western part of the UP and Schoolcraft in the eastern part. These populations possibly entered Michigan from adjacent Wisconsin post-glacially. This turtle is widely distributed in the lower half of the Lower Peninsula of Michigan. The lack of records for Northern Map Turtles in a few central Lower Peninsula counties may be from a lack of systematic scientific surveying in these areas. In the upper third of the Lower Peninsula, Northern Map Turtles are recorded from at least two counties, Roscommon and Grand Traverse. Map Turtles are not rare in shallow, well-vegetated areas of lakes in Grand Traverse County (Douglass 1977 and my own observations), but I am not aware of an abundance of this species in Roscommon County. Of interest is the fact that Map Turtles have not been observed by either J. F. Douglass or myself in rivers or streams in Grand Traverse County.

FIG. 72. Hatchling Northern Map Turtle (Graptemys geographica) from Michigan. Photograph by James H. Harding.

Geographic Variation No distinct populations of Northern Map Turtles have been described from Michigan; moreover, no subspecies are recognized throughout the wide range of Graptemys geographica. Ernst and Lovich (2009) found that the lack of mitochondrial DNA variation in this species was unusual, considering its wide range. Thirteen (and perhaps more) species of Graptemys are recognized in North America, more species than in any other genus on the subcontinent.

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Habitat and Habits The Northern Map Turtle is highly aquatic and prefers rivers and lakes. Ruthven et al. (1928) reported that this turtle is more likely to be found in lakes than in rivers in southern Michigan, but I have not found that to be the case in the Lansing area—just the opposite, as a matter of fact. Harding (1997) reported that in the Great Lakes region, Northern Map Turtles live in the larger lakes, rivers, reservoirs, oxbows, sloughs, and open marshes. He mentions that they also inhabit bays and inlets of the Great Lakes themselves. Bottom substrates range from soft mud to sand and gravel, and the aquatic situation can be highly vegetated or rather open. Northern Map Turtles are not averse to pollution. I have observed for thirty-seven years what I consider to be a moderately healthy population of these turtles in the Red Cedar River, both on the Michigan State University campus and in the greater Lansing area. When I first came to East Lansing, this river was highly polluted, yet Map Turtles were moderately common in those days. The river is much cleaner now and has been for at least the last decade, yet the Map Turtle population appears to be about the same. In my youth I was surprised to see that Northern Map Turtles were moderately common in the polluted White River in Indianapolis, and not long ago I observed them again in the city part of that river. Minton (2001, 194) stated that “this turtle adapts better than many species to human modification of its habitat and often follows large streams into cities.” For more than forty years, Minton (2001) observed a population of Northern Map Turtles that inhabited the Indianapolis Water Company Canal and made some interesting observations. Some of these turtles were seen as early as February, but large numbers were often seen in May and early June. He never saw hatchlings, but he observed many juveniles with three-inch shell lengths. From 1964 to 1970, basking aggregations grew smaller. After 1978, adults were rarely seen and juveniles were only occasionally observed. The last adults were observed in July 1996. Factors Minton associated with this decline were reinforcement of the canal banks with rocks, removal of fallen limbs and aquatic vegetation from the canal, and the introduction of large numbers of ducks. In southern Michigan, Northern Map Turtles are usually first observed basking some time in April. But I find they come out to bask later in the month than

2. Species Accounts

do Painted Turtles or Blanding’s Turtles, at least in the Lansing area. In general, basking in this species occurs on emergent logs, tussocks, boulders, sloping muddy banks, sand bars, and especially emergent brush piles. In the Red Cedar River on and near the Michigan State University campus, I have seen juveniles basking on discarded tires and snagged material on abandoned grocery carts. The MSU turtles of all ages seem to be much less alert to the presence of humans than those in other parts of the Red Cedar River. Still, the adults are most alert, the juveniles less so, and the hatchlings least of all in this setting. Northern Map Turtles are active mainly in the daytime but often have more retiring habits as the days begin to get hot later in the summer. Harding (1997) reported that these turtles may feed in the evening or even after dark during the warm months of summer in the Great Lakes region. Here, Northern Map Turtles quit feeding and are generally dormant from early November through early April. During this interval, they spend most of their time underwater—beneath logs or other large objects such as a sunken wooden boat mired in mud—or in muskrat burrows. They often change these locations and in winter may be seen crawling about slowly under the ice. In northern Indiana, Evermann and Clark (1920) saw Northern Map Turtles in Lake Maxinkuckee walking on the bottom under the ice. They counted sixty-nine individuals on Christmas Day in 1900. Minton (2001) has seen this species in Indiana basking in every month except for December and January. Reproduction and Growth Oddly, detailed reports of courtship and mating in the Northern Map Turtle are lacking. Harding (1997) suspects that mating may occur in deep water where the animals cannot be observed. Evermann and Clark (1916) reported that in Indiana courtship and mating presumably occur in both spring and fall. They reported that on October 4 and then later, a pair of Map Turtles, a small one following a large one, was seen walking on the bottom of Lake Maxinkuckee and that on April 27 smaller ones were seen trailing large ones again, as if they were going to mate. It is known that in the Great Lakes region nesting lasts from May through early July, with mid-June being the peak (Harding 1997). Females normally leave the

water to look for nesting sites early in the morning or late in the evening. However, warm rains may sometimes stimulate nesting activities in the middle of the day. Sunny sites with sandy or loamy soils are selected, and females may move away from the water up to several hundred meters to find good sites. The nest is flaskshaped, and the female digs the nest with her back feet. Six to twelve oval, rather soft eggs are laid. These eggs become firmer as they absorb water during incubation. The eggs range from 32 to 35 mm (1.26–1.38 in.) in length. In Indiana, females have been observed to flatten the top of the nest with the plastron (Newman 1906). Some females will lay two clutches of eggs per season. Hatching occurs about two months after oviposition, and in the Great Lakes region, the young usually emerge from the nests in August or September. The hatchlings, like those of the Painted Turtle, may overwinter in the nest and emerge in the spring (Gibbons and Nelson 1978). Northern Map Turtles have temperaturedependent sex determination (TSD). In the laboratory it has been shown that a predominance of males results from an incubation temperature of 25ºC (77ºF). At an incubation temperature of 30ºC (86ºF), females predominate (Bull and Vogt 1979; Ewert and Nelson 1991). Eggs manipulated by humans but in a natural setting produced mainly males when put in the shade and mainly females when put in the sun (Bull and Vogt 1979). In natural nests studied in Wisconsin, 21 percent of hatchlings were males (Vogt and Bull 1984). I am unaware of any such studies in Michigan. Gordon and MacCulloch (1980) showed that in Quebec females grow significantly faster than males, which is not surprising considering the large size of the females relative to that of the males. Growth rings were used to make the determinations. In Indiana, Iverson (1988) showed that females grew larger than males after their second year and that both sexes averaged larger adult sizes than the Quebec turtles. Diet Mollusks are considered to be a very important part of the diet of Northern Map Turtles (see citations to many studies in Ernst and Lovich 2009). Garman (1890, 12) commented on the feeding habits of Graptemys geographica, probably from the vicinity of Lexington, Kentucky: “The examination of the contents of the digestive tube

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134

of M. geographicus throws light at once in the modification of the jaws and head. In all those I examined the food consisted exclusively of mollusks, in the young turtles consisting of Valvata tricarinata and other thin-shelled species, in the adults of larger and thicker-shelled forms.” The broad surfaces of the jaws in this species are specially adapted for this type of feeding. In Michigan, Lagler (1943) found that crayfish, mollusks, and insects were the Map Turtles’ principal food. This data was based on stomach or colon studies of twenty-seven turtles from “natural waters” in six lakes, four rivers, and “some unknown waters.” In Wisconsin, Vogt (1981) found that Northern Map Turtles eat mainly mollusks, as these were found in 81 percent of the stomachs studied. Other important material eaten consisted of fishes, caddis flies, mayflies, damselflies, and a little plant material. Vogt pointed out that the predominantly mollusk-eating food habits of the Northern Map Turtle help it to avoid competition with the sympatric (co-occurring) map turtle species G. pseudogeographica and G. ouachitensis, both of which feed principally on insects and plant material. In Indiana, Newman (1906, 140) observed Northern Map Turtles using two methods for feeding on mollusks: “The favorite method seems to be to capture the mollusc when the foot and the gills are well out of the shell, to bite off the soft parts and leave the hard shell. To do this the final closure of the jaws must be quite sudden. If they fail to secure the body of the snail in this way they adopt the crushing method. The hard shell is easily crushed between the broad flat jaws and the broken pieces of shell are picked out with the aid of the claws.” In Lake Erie habitats associated with a Pennsylvania sandpit peninsula, adult male Graptemys geopraphica fed mainly on tricopterans and snails, whereas the larger females fed almost entirely on zebra and quagga mussels of the genus Dreissena (Lindeman 2006).

shelters for these turtles when they are underwater (James C. Gillingham, pers. comm., and my own observations). On land, however, even adults are at risk from mammalian predators. Cochran (1987) found the remains of thirteen adult female Northern Map Turtles (and bones of other turtles, probably Map Turtles) in Minnesota over a period of five days. Predators in the area included opossums, raccoons, skunks, and coyotes. I have seen “plinkers” (people who shoot small animals with .22-caliber rifles to “sharpen their shooting skills”) shoot at Map Turtles in Alabama, Indiana, and Michigan. The shyness of the Map Turtles supposedly tests the skill of the shooters. This activity is a deplorable waste of wildlife resources and is illegal in Michigan.

Predation and Defense The eggs and hatchlings of the Northern Map Turtle are preyed upon by many vertebrate predators, as in other turtles. In Michigan, this species usually slides quickly into the water from its basking site at the first sign of danger. Basking sites are often composed of or are near piles of brush, which make excellent protective

Population Health This species is not on the Threatened or Endangered lists in Michigan, but as previously stated some populations have been reduced or eliminated by pollution, shoreline development, or unthinking individuals who use turtles for target practice (Harding and Holman 1997).

Interaction with Humans Northern Map Turtles are no threat to game fish and otherwise do not interact negatively with humans. In fact, people in the state enjoy seeing these animals basking at the edges of rivers and lakes. Their snail-eating habits may be beneficial to humans, as snails are the intermediate host of trematodes that parasitize domestic and game animals as well as the blood fluke that causes swimmer’s itch (Harding 1997). The Northern Map Turtle’s consumption of the invasive zebra mussel is presumably of benefit to humans as well. According to Harding, populations of Map Turtles have been reduced or eliminated in some areas of the Great Lakes region mainly or in part because of pollution and destruction of nesting sites. Northern Map Turtles that live in lakes are sometimes injured or killed by boat propellers and personal watercraft. Behavioral Characteristics For the behavioral characteristics of Northern Map Turtles, see the sections “Habitat and Habits,” “Reproduction and Growth,” “Diet,” and “Predation and Defense” in this account.

2. Species Accounts

General Remarks An additional point about the shooting of turtles for target practice is that a normal .22-caliber bullet, used for “varmint killing” of animals such as raccoons and woodchucks, can carry a mile or more. I wonder if people who shoot turtles off logs and brush piles realize they might accidentally hit humans or pets in the process, even if they aren’t concerned about depleting the turtle population.

Terrapene carolina carolina (Linnaeus 1758) Eastern Box Turtle Identification The Eastern Box Turtle is the only Michigan turtle that can completely close its shell over all parts of its body—unless it eats too much and gets fat, which is almost universal in captive specimens and not entirely rare in the wild. It is also the most terrestrial turtle in the state. The carapace is dome-shaped and looks like a helmet or hardhat. The carapace has a rather weak keel along the midline, and the epidermal scutes have growth rings except in old animals, which have a smooth carapace. The coloration of the carapace is somewhat variable, but it is usually some shade of brown with a radiating pattern of yellow or orange blotches, spots, or lines on each epidermal scute. In some Eastern Box Turtles, there is so much yellow on the carapace that they appear to be yellow animals with dark markings. The plastron has a distinct hinge that allows complete closure of the two lobes that form the closing structure. Male Eastern Box Turtles have red eyes and females usually have brown. The hind lobe of the plastron of males is concave and that of the female is flat or slightly convex. In Michigan, the adult carapace length ranges from 112 to 198 mm (4.41 to 7.80 in.) (Harding and Holman 1997). General Distribution The Eastern Box Turtle ranges from Massachusetts to southern Georgia, westward along the southern portion of the Great Lakes region to west central Illinois, and south to northeastern Mississippi. Other subspecies of Terrapene carolina occur south and west of the eastern form.

Michigan Distribution Eastern Box Turtles in Michigan are absent from the Upper Peninsula, and they do not occur naturally on any Michigan islands. In the Lower Peninsula they occur in the southern three tiers of counties and in the counties on the western (Lake Michigan) side, up to Leelanau County and inland to Ionia, Isabella, and Clare counties. They have been extirpated from many parts of their former range in the state but remain most common in the southwestern counties. Where box turtles occur, numerous remains of individuals killed by cars are too common. I have seen numerous roadkill specimens in southwestern Michigan, but after years of patrolling the roads in northwestern Michigan, I have seen no box turtle remains on the road, suggesting that the turtles are much scarcer in the area. However, I found a mature female Eastern Box Turtle crossing State Road about a quarter of a kilometer (0.16 mile) east of Fife Lake Village in extreme southeastern Grand Traverse County on August 16, 2004. I released this specimen in woodlands across the road from where she was found. This species has not been previously recorded from Grand Traverse County, although the Michigan Natural Features Inventory has recorded this species from adjacent Wexford County to the south. Thus this Grand Traverse specimen may represent a range extension, but it is also possible that it was a released or escaped captive specimen. At the time of capture (9:40 a.m.) the day

Fig. 73. Eastern Box Turtle (Terrapene carolina carolina) from Muskegon County, Michigan. Photograph by James H. Harding.

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was overcast and the temperature was only 57ºF, a rather dismal setting for Eastern Box Turtle travels. Also, the location was bordered on the other side of the road by a row of cottages. Box turtles appear to be absent from the thumb area of Michigan, the counties bordering Saginaw Bay, and the other eastern Michigan counties north of the three southern tiers. Geographic Variation No genetically distinct populations of Eastern Box Turtles have been recognized in Michigan, but three other subspecies of Terrapene carolina are recognized, two in the Deep South (Terrapene carolina bauri and T. c. major) and one that is mainly west of the Mississippi River (T. c. triunguis). (See Dodd 2001, page 35, for a diagram of the evolutionary relationships of the species and subspecies of box turtles.) In the Pleistocene, a giant subspecies of box turtle, T. carolina canaliculata, occurred from Florida to Texas (Auffenberg 1958; Holman 1995b). This fossil species is probably most closely related to the Gulf Coast subspecies T. c. major (Auffenberg 1958). Habitat and Habits In Michigan, the Eastern Box Turtle is mainly found in rather open broadleaf forest situations, especially when these woodlands have such features as ravines and slopes. Box turtles do not usually live far from water and often soak themselves in shallow ponds and pools during the hot days of summer. Michigan populations of the Eastern Box Turtle usually become active in April but may not be seen until early May. They go into hibernation from late September through October, depending on the weather. Michigan Terrapene c. carolina are most active during the spring and early fall, which are times when they may be frequently seen crossing the roads in the state. During the summer they are briefly active in the early part of the day and during periods of rain. During these summer spurts of activity they appear to be “busy” and waddle across the roads at what appears to be their highest speed. During their activity periods in the spring and fall, they often stop on the road to sun, and if cars pass close by they are apt to withdraw into their shell, only to be hit by the next passing vehicle. Eastern Box Turtles tend to be associated with piles of deciduous leaf litter

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and spend much of their time, especially on hot summer days, buried under damp piles of this litter. I have found them in such piles with just the top part of the carapace showing, which incidentally blends in very well with the litter and other parts of the forest floor. Dodd (2001) states that Box Turtles are capable of swimming both at the surface and underwater, and he quotes several sources for this information back as far as Overton (1916). I suspect that most of this swimming occurs in quiet, shallow water. As a child in Indiana, I unwittingly put an Eastern Box Turtle in the water at the edge of a stream in Turkey Run State Park, reckoning that the animal would swim away and hide at the bottom like other turtles I had come across. Instead, I was horrified as it was caught up in the current and bobbed about helplessly as it drifted downstream. Finally, in a slow stretch of water, it paddled in an ungainly way to a sandbar. When Eastern Box Turtles enter hibernation, they generally burrow into loose soil, sand, or vegetable debris. They also enter mammal burrows. As the temperature drops, they typically dig themselves in deeper and may go as deep as 600 mm (23.62 in.) (Ernst and Lovich 2009). In Ohio, hibernation lasts about 142 days (Clausen et al. 1991). While in Indiana, I maintained four Eastern Box Turtles in an outdoor enclosure for eight years. These turtles attempted to dig into the hard clay soil every fall to no avail. For the first four years I put them in a box of litter in an apple cellar, and they were emaciated when spring came around. On advice from a local herpetologist, the next year I dug an eighteen-inch hole in the enclosure, put straw from my father’s victory garden on the bottom and covered the four turtles with leaf litter compost. For the next four years they emerged in good shape every spring. If the weather remained warm, the turtles became very active in just a few days. Recent studies have shown that Box Turtles can survive partial freezing (Costanzo et al. 1993; Dodd 2001, 53), so perhaps this may have saved my four Box Turtles during one severe winter cold spell in Indianapolis. Minton (2001, 186) reported that “box turtles survived several winters, one very severe, in our window wells at Indianapolis. They buried themselves under about three inches of rotting leaves, but their carapaces were never completely below the surface of the soil.”

2. Species Accounts

A long-term study of marked Eastern Box Turtles in Maryland by Stickel (1950, 1989) showed that males occupied an area of 1.13 ha (2.79 acres) and that females occupied an area of 1.32 ha (3.26 acres). Nichols (1939) found that 89.5 percent of the adult Box Turtles that he studied showed some homing tendencies. Gould (1957) found that twenty-two of forty-three Terrapene carolina individuals moved toward home when they were let go in open fields up to 3 km (1.86 miles) from their original place of capture. These turtles oriented themselves by the sun, and homeward movements were either lacking or inaccurate on overcast days. Light reflected on them from a mirror caused them to change directions. Other studies have suggested that “internal clock” and time-dependent celestial cues (De Rosa and Taylor 1982) and geomagnatism (Mathis and Moore 1988) might influence Box Turtle orientation. Territorial defense has never been proven in Eastern Box Turtles. Reproduction and Growth In the Great Lakes region, Eastern Box Turtles may breed anytime during their season of activity, although breeding is most frequent in the spring or fall (Harding 1997). Male hierarchical dominance, as far as I know, has never been proven in the field, but in groups of turtles kept in outdoor enclosures, aggression between males can occur, and one or two males often do most of the mating. The courtship of Terrapene carolina has been divided into three phases (L. T. Evans 1953; Ernst 1981; Levell 1985). The phases are (1) circling, biting, and shoving; (2) preliminary mounting; and (3) intromission (a coital stage). An account of these phases slightly modified from the published reports follows. In the first phase, the male approaches the female but stops a few inches away if she remains motionless. The male holds his head high with one leg off the ground. The female then retracts her head. The male then walks around the female, biting at her head, tilting her shell upward, and biting at the edge of her carapace. If the female moves away, the male chases her with his neck extended and appears to smell the back of her shell and tail. The male may or may not tip her over during this part of the phase. Phase 1 may last five minutes or less, or up to one hour, depending on the readiness of the female to mate. Sometimes the female closes up her shell and attempts to “wait out” the male. But if they are the only two turtles in an

area, it is likely to be a very long wait, for male Box Turtles are tenacious in their lovemaking. The male eventually mounts the female and quickly hooks his toes into the opening of the back of the shell of the female. The male then titillates his front claws on the edge of the carapace of the female. Typically, this is the final stimulus that causes the female to open the back end of her plastron. In phase 2 the male’s hind feet explore the edges of the female’s plastron in a forward direction until they are near the hinge. The claws then hook on, and the female closes her plastron on the feet of the male. The stimuli that initiate phase 3 are the contact of the plastron with her carapace, the downward movement of the head of the male to a position in front of the female’s face as he nips at the forward edge of her shell, the contact of his forefeet on her shell, and the subtle motion of his trapped claws on the edge of her plastron. To initiate copulation, the male moves backward until his carapace touches the substrate, while the hind ankles of the female push downward upon his feet, which have moved farther under her carapace. After a few seconds he leans very far back until he is in a vertical position and his penis is inserted into the female’s cloaca. I have always suspected that the concave plastra of male Eastern Box Turtles helps them mount the domed carapace of the female, at least in the preliminary stages of the mounting process. All of the male Three-toed Box Turtles (Terrapene carolina triunguis) I have seen have flat plastra, and I have watched captive male Three-toed Box Turtles try to mount female Eastern Box Turtles and only slide off their backs in the attempt. However, this behavior occurred in captivity, and I have no idea whether or not this would occur in the wild. Nesting in the wild in Terrapene c. carolina takes place in June in Michigan (Harding and Holman 1997). Females are able to lay fertile eggs up to four years after a single mating. Nests are usually started in the afternoon and finished after dark. Stickel (1950) reported that nest sites of Eastern Box Turtles were sometimes outside the normal home range of the female. Nests are normally dug in open, elevated patches in sandy or loamy soil, but some females nest in the woods (Ernst and Lovich 2009). The nest is flask-shaped and dug entirely with the back feet. Congello (1978) reported that most nests are dug on stormy evenings, perhaps to benefit from the rain

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that may facilitate digging the nest or to hide the odor of the female from predators. The eggs of Eastern Box Turtles are laid in intervals of one to six minutes and are arranged in the nest by the hind feet of the female. The nesting process sometimes takes as long as five hours to complete (Ernst and Lovich 2009). The eggs are 24.5 to 40.2 mm (.96–1.58 in.) in length and 17 to 25.1 mm (.67–.99 in.) in width. The eggs are elliptical, white, and flexible. Terrapene c. carolina may occasionally lay two clutches of eggs a year in Michigan; clutch size ranges from two to eleven, but five to seven eggs per clutch is more usual. Terrapene carolina has temperature-dependent sex determination (TSD). When clutches of their eggs are incubated at temperatures of 22.5 to 27.0ºC (72.5– 80.6ºF) the hatchlings are mainly males. When eggs of this species are incubated at 28.5ºC (83.3ºF) almost all of the hatchlings are females (Dimond 1983; Ewert and Nelson 1991). Hatchling Terrapene carolina have a carapace length of about 28 to 35 mm (1.10–1.38 in.). The hinge is not functional in hatchlings and does not become so until the animal reaches about 55 mm (2.17 in.) in length (Holman 1985; Ernst and Lovich 2009). Neill (1948) stated that during the early months of their lives, young Terrapene carolina give off a strong odor when they are bothered and that the odor is lost later in life. Ernst and Lovich (2009) have not noticed this, nor have I. On the other hand, people differ in their ability to distinguish various odors. Harding (1997) commented on growth in Eastern Box Turtles in the Great Lakes region. He stated that for the first few years of life this species can grow about 10 to 20 mm (0.39–0.79 in.) per year but that growth slows down after maturity is reached. He mentions that sexual maturity may sometimes be reached in five or six years but can require ten years or more in the northern part of its range; in most of the Great Lakes populations, breeding adults will be more than fifteen years old.

an authentic report related to me in 1967 by M. M. Hensley, a herpetologist in the Zoology Department of Michigan State University takes the cake. He said that a local professor had taught his male Box Turtle to assume the upright mating position whenever food was offered. In other words, the turtle rocked back in a vertical position, balancing itself with its long and extended back legs in a begging behavior. I never saw this behavior myself, but I have never doubted Dr. Hensley’s veracity. Hatchling and juvenile Box Turtles are mainly carnivorous but become more herbivorous as they age. I reported on a tiny Terrapene c. carolina from Georgia that retained a rigid plastron and never developed a hinge during the four months of its captivity, although its shell increased about 19 percent in length (Holman 1985). This turtle could be induced to eat only small earthworms, which were most readily accepted when the turtle was allowed to swallow them under 8 mm (.31 in.) of water in a petri dish. The turtle measured 28.0 mm (1.10 in.) in carapace length on May 2, 1982, and 35.5 mm (1.40 in.) when it died suddenly from unknown causes, December 8, 1982. Feeding habits of Eastern Box Turtles in the wild are well documented. Eighty percent of the stomachs of forty Pennsylvania Box Turtles that had food in them contained animal remains and 62 percent contained plant remains (Surface 1908). Ernst and Lovich (2009) listed a tremendous variety of plant and animal material eaten by this species, including roots, stems, fruits, seeds, berries, mosses, fungi, snails, slugs, earthworms, spiders, isopods, millipedes, crayfishes, centipedes, wood roaches, grasshoppers, crickets, flies, beetles, ants, termites, cicadas, moths, caterpillars, insect grubs, and even maggots. Vertebrate foods include fish, frogs, toads, salamanders, lizards, small snakes, and birds. They also eat carrion. Box Turtles are potential seed scatterers, as they drop their seed-bearing feces about as they travel through the woodlands (Braun and Brooks 1987).

Diet The breadth of diet of these consummate omnivores can be summed up by stating that Eastern Box Turtles will eat almost anything that is eaten by humans and a good many things that most humans would decline. Several people who have had Box Turtle pets have told me about the turtle training they did relative to feeding time. However,

Predation and Defense Box Turtles have a large number of avian and mammalian nest predators (Ernst and Lovich 2009), many of which live in Michigan, including badgers, skunks, foxes, raccoons, crows, ravens, and vultures. Snakes, including the Racer, Coluber constrictor, a species that lives in Michigan, also feed on the eggs. Numerous

2. Species Accounts

limb mutilations seen on Box Turtles are probably from encounters with raccoons, skunks, coyotes, and feral dogs. The best defensive mechanism the Eastern Box Turtle has, other than its protective coloration in the woods, is to retract the head, limbs, and tail completely within the shell. Parenthetically, Box Turtles seem to have a strong odor that attracts dogs, which often pick up the turtles and carry them around, for some reason or another. In Indiana, bird dogs that point turtles, or worse yet carry them around, are not looked upon with fondness and good humor. Dodd (2001) recalls the work of Charles and Elizabeth Schwartz, who did excellent field studies of Three-toed Box Turtles in Missouri. The Schwartzes perfected a method of using dogs to find the turtles that were then marked or retrieved. Now and then an Eastern Box Turtle is found in the field that is infested with flesh fly larvae, which burrow under the turtle’s skin and cause ugly infected pockets. Sometimes these infections can be fatal to the turtles. Interaction with Humans Humans have interacted amiably with Box Turtles in North America for many years. I certainly have met none with a grudge against them except for a few gardeners who have had the turtles sample their ripe strawberries. Dodd (2001) summarizes Box Turtle interactions throughout human history, including the use of these turtles by prehistoric peoples and modern Native Americans and the importance of these turtles in art and illustration. He mentioned the abundance of Box Turtle remains in prehistoric archeological sites and the continued use of these remains in ceremonial functions of Native Americans today. He discusses how Box Turtles have been incorporated into sculptural stonework and casts of bronze figures as well as in carvings made from many kinds of wood. He also points out how modern Native American artists have made carvings of Box Turtles that have blended the real with the spiritual. Adler (1970) has suggested that American Indians, primarily the Iroquois, were responsible for the extirpation of Eastern Box Turtles in western New York and possibly southern Ontario. These turtles were used for food, ceremonial, medical, and other purposes by the Iroquois. A discussion of Eastern Box Turtle remains in Michigan archaeological sites is included in part 3.

This species is in high demand in the pet trade, both in North America and internationally. Eastern Box Turtles are protected by MDNR regulations, and collection, possession, and sale is illegal in Michigan. Within their Michigan range, Eastern Box Turtles sometimes survive in small areas, such as woodlots, old fields, and parks. In the years to come, however, these small populations may not survive, especially if they are collected as pets, or if road mortality significantly reduces their numbers. Harding (1997, 201) summed it up well when he stated that “box turtles are afforded varying degrees of legal protection throughout the [Great Lakes] region, but these laws fail to protect them from their worst enemies, bulldozers and automobiles.” Behavioral Characteristics For the behavioral characteristics of Eastern Box Turtles, see the sections “Habitat and Habits,” “Reproduction and Growth,” and “Diet” in this account. Population Health Box Turtles need protection all over their range, and in 1994 they were added to Appendix 11 in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) agreement. This international agreement prohibits export of Box Turtles and regulates the commercial trade in such animals. In Michigan, under the Director’s Order No. DFI-166.98, “Regulations on the Take of Reptiles and Amphibians,” it is unlawful to take a Box Turtle from the wild except as authorized under a permit from the director of the MDNR. According to D. A. Hyde in a 1999 abstract for the Michigan Natural Features Inventory, conservation efforts for the Eastern Box Turtle in the state should deal with the protection of large tracts of habitat on public land to provide this turtle additional protection from the effects of development. Moreover, wetland hydrology and quality should be ensured to protect improper off-road vehicle use in these areas as well as the controlling of invasive weeds. Also, upland nesting areas should be identified and protected, and in some situations new nesting areas should be created. New roads should be routed to avoid separating the turtle’s habitat from its nesting areas. Finally, the local public must be informed about the laws that protect amphibians and reptiles and be urged to leave the turtles in their natural habitat rather than taking them home as pets.

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General Remarks Oliver (1955) stated that a Terrapene carolina lived 138 years in the wild. Graham and Hutchison (1969) provided evidence for one-hundred-year-old Eastern Box Turtles in New England. Nevertheless, Stickel (1978) and Ernst and Lovich (2009) have suggested that only a few wild Terrapene c. carolina live more than thirty or forty years.

Trachemys scripta elegans (Wied-Neuwied 1838) Red-eared Slider Identification The Red-eared Slider is a medium to large aquatic turtle with an olive or greenish brown carapace that has a variable pattern of black and yellow bands and stripes. The posterior carapace is weakly to moderately serrated (notched). The plastron is yellow with a dark spot or blotch in the center of each epidermal scute. The head and legs are green, olive, or a brownish color, interrupted by many yellow stripes. The large red or orange stripe that extends backward from each eye is a characteristic field mark that has resulted in the common name of this turtle. Some care must be taken when identifying large male Red-eared Sliders because they can often become a very dark color that masks the regular color pattern of the species. The adult carapace length of this turtle ranges from about 125 to 289 mm (4.92–11.38 in.). Male Red-eared Sliders are smaller than the females and have much longer front claws and tails. General Distribution When I was a child, small Red-eared Sliders were sold in every dime-store pet shop, usually for twenty-five cents apiece. Often their backs were painted (see C. H. Pope 1939, plate facing p. 27), and they died either from the paint job or from starvation because they would not eat the dried ant eggs sold as turtle food by the pet stores of the day. These little turtles were exported by the pet trade all over the world, where today they exist as unnatural populations in such places as Japan, Germany, Israel, South Africa, and the Mariana Islands (Ernst and Lovich 2009). They are considered pests in France and other European countries, where they may compete for habitat with the rare European Pond Turtle (Fritz et al. 1998).

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Evidently the underfed tiny turtles survived the dingy pet shops and swirling toilet bowls to conquer the turtle world. The natural distribution of the Red-eared Slider is from West Virginia west to northern Indiana and Illinois, and south to the Gulf coastal states from west Georgia through Texas as well as northern and eastern New Mexico. Isolated populations of this turtle exist in California, Maryland, southern Ohio, southern Michigan, and southern Ontario as well as other locations that have not yet appeared in field guides. Other subspecies of Trachemys scripta extend the range to eastern Tennessee and the southeastern states from Virginia to Florida; the species also ranges from Mexico into South America. Michigan Distribution I have raised two questions about the Red-eared Slider in Michigan (Holman 1994): (1) Is the animal native or introduced? and (2) Are existing populations successfully maintaining themselves? Regarding the first question, the most frequent answer is that the species has indeed been introduced through the release of pet-shop turtles (Holman and Harding 1977; Harding and Holman 1997). However, a second possibility is that some of these turtles are relicts from warmer mid-Holocene times. Adler (1968) documented the occurrence of

FIG. 74. Red-eared Slider (Trachemys scripta elegans) from the Red Cedar River, Michigan State University campus. This turtle was kept in a managed pond near the river, and she produced several viable clutches of eggs. Photograph by James H. Harding.

2. Species Accounts

Red-eared Slider remains from the Schultz Archaeological Site in Saginaw County, Michigan. The bone was a posterior peripheral bone that can easily be identified from related turtle species on the basis of its strong double indentations. The Schultz Site was occupied from about 2,500 to about 1,600 ka BP during the Early and Middle Woodland Periods (Cleland 1966). Here, a warm-water fishery existed in sluggish, wellvegetated backwaters. I strongly believe, as did Adler, that this bone was not from material introduced by intertribal trade. The Slider bone was recovered among the refuse of local animals used as food; it was not used as an ornament. Adler (1968) suggested that his record and another from the Durst Archaeological Site at about the same latitude in south-central Wisconsin suggests that the range of the Red-eared Slider has been reduced in subsequent times. Word-of-mouth accounts about the occurrence of Red-eared Sliders in southern Michigan are many but records documented by specimens or photographs are few. The following list contains the documented Michigan county records of the Red-eared Slider: Muskegon County: Crystal Lake, Duck Lake, and near Whitehall (Edgren 1943, 1948; Gordon and Fowler 1961). These are thought to be introduced populations. Oceana County: North Branch of White River (Edgren 1948; Gordon and Fowler 1961). It has been suggested that this record might indicate an extension to the south of the range of the introduced populations. Ingham County: Two locales on the Red Cedar River, plus many verbal reports (Holman 1994). One of these specimens was removed to a managed outdoor pond in Ingham County and has reproduced successfully several times. Washtenaw County: Pond at Fish Research Station, Saline, Michigan (Holman 1994). One adult specimen was captured alive when the pond was drained in December 1992. Oakland County: Cranbrook Lake, Green Lake (Gordon and Fowler 1961; Holman 1994). Gordon and Fowler commented that the retaking of a 1958 individual in 1959 suggests that the species at Cranbrook Lake could survive the winters at this

latitude and might eventually become established. James H. Harding (in Holman 1994) observed a population of Red-eared Sliders at Green Lake from the early 1970s through 1984. The species is common there and specimens of all sizes have been seen and frequently captured by local residents. I saw several individuals there when I visited the site with Harding in 1983. As mentioned previously, in my 1994 publication I suggested the alternative hypothesis that at least some of the Red-eared Slider populations in Michigan may be relicts from ancient times when the species was more widely distributed. We await genetic studies that may confirm or deny this hypothesis. On the other hand, I think there is no question that some successfully breeding populations of Red-eared Sliders presently occur in southern Michigan. If we really are in for a long-term global warm spell, then it seems possible that Sliders may extend their range in Michigan. Geographic Variation Nothing has been published on geographic variation within Trachemys scripta elegans as far as I am aware. Habitat and Habits Red-eared Sliders prefer sluggish or still-water habitats with abundant aquatic vegetation and numerous basking sites, habitats that are presently used by Painted Turtles in Michigan, although the larger Sliders may tolerate somewhat deeper water. In Indiana, Minton (2001) reported that before 1970 there were no records of Redeared Sliders from Indianapolis and Marion County, even though Minton and others did considerable fieldwork in the area. He wondered whether the change was because of a proliferation of small, natural populations or expansion of populations released as pets. Minton (2001, 208) made this comment about the ability of Red-eared Sliders to find new habitats: “The turtles do seem to find new habitats quickly. In the summer of 1989, a small lake was constructed near our home in northeast Indianapolis. On October 10, an adult male Trachemys was killed crossing the street bordering this lake. On October 13, another adult male was taken at the same place. The following May an adult female was found in a nearby yard. The nearest known population of Red-ears is in White River about two miles away,

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but there are possible habitats in Fall Creek and another artificial lake less than a half mile away.” Reproduction and Growth Red-eared Sliders are prolific breeders, laying up to thirty eggs per clutch (though ten eggs would be closer to average) and, in the Great Lakes region, sometimes producing a second clutch from two to four weeks after the first (Harding 1997). This animal has temperature-dependent sex determination (TSD), and nest temperatures at about midway through incubation determine the sex of the offspring. Eggs that were incubated at constant temperatures between 22.5 and 27ºC (72.5–80.6ºF) produced only males, whereas eggs incubated at 30ºC (86ºF) produced females. Males can reach sexual maturity in two to five years at a carapace length of about 125 mm (4.92 in.), and females mature in six to eight years at a carapace length of about 180 to 200 mm (7.1–7.9 in.) (Harding 1997). Diet Minton (2001) reported that in Indiana, young Redeared Sliders are predominantly carnivorous, whereas adults are omnivorous. He stated that emergent aquatic plants and duckweed are often eaten and that their animal foods include snails, crayfish, aquatic insects, frog larvae, and fishes. Predation and Defense Harding (1997, 218) stated that “Red-eared Slider eggs and hatchlings are readily consumed by raccoons, skunks, and other predators; typical mortality rates for eggs and new hatchlings range from about 70 percent to nearly 100 percent in any one year or place.” In experiments, it was found that live hatchling Sliders were spit out by largemouth bass but that dead ones were quickly eaten by these predatory fish (Semlitsch and Gibbons 1989). This suggests the possibility that the behavior of the hatchlings (possibly clawing and biting at delicate gills structures on the way to the stomach?) might discourage predation by bass and other large fish. Interaction with Humans The most important interaction with humans relative to the Red-eared Slider concerns the effects of the introduction of this species on a worldwide basis. In

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some areas, these turtles allegedly compete with other turtles, especially in some of the European countries where the native Pond Turtle (Emys orbicularis) is rare and may vie with Sliders for habitat space (Fritz et al. 1998). Minton (2001) has pointed out that domestic trade in baby turtles (a preponderance of these were Red-eared Sliders) was halted in 1972 because of the danger of Salmonella infections. But he also cited the Federal Register of March 21, 1989, which provided the data that “two to three million baby turtles are exported annually and about 400,000 adults are exported for food” (Minton 2001, 210). Behavioral Characteristics For the behavioral characteristics of the Red-eared Slider, see the sections “Habits and Habitat” and “Diet” in this account. Population Health Red-eared Sliders are not specifically listed by the MDNR, and apparently no comprehensive statewide surveys of the species have yet been made. General Remarks I see no reason for concern about the few probable breeding populations of Red-eared Sliders in Michigan, even if they prove to be introduced rather than native relict populations. There would seem to be little significant niche overlap between the Slider and the rarer and more sensitive turtle species in Michigan. Some evidence indicates that during the Quaternary period in southwestern Indiana, Emydoidea blandingii, which was common in the Pleistocene, was replaced by Trachemys scripta in the Holocene (Holman and Richards 1993). I am hesitant to say, however, that this was based on competition between the two species. Today in Michigan, the Painted Turtle, though more ubiquitous in its choice of aquatic situations, shares some habitats with Blanding’s Turtle. However, this overlap would seemingly have nothing to do with the diminishing populations of the latter species.

Family Kinosternidae The Family Kinosternidae includes the musk and mud turtles, which are small to large aquatic, bottom-walking turtles that occur from Canada to South America. The

2. Species Accounts

family is composed of four genera: Claudius, Kinosternon, Staurotypus, and Sternotherus. Claudius and Staurotypus are tropical turtles, Kinosternon is both tropical and North American, and Sternotherus occurs only in the United States and Canada. Kinosternid turtles probably evolved in Mexico or Central America and eventually migrated southward and also northward to the United States, with one of these species eventually making it to Canada. The plastron of these species varies from having one (fleshy) hinge in Staurotypus, Sternotherus, and some Kinosternon, two hinges in most Kinosternon, or no hinge at all in Claudius. The family has only ten or eleven epidermal scutes on the plastron. Musk glands that secrete an unpleasant odor are associated with the bridge area of the shell. All of these animals have barbels on the chin that have a sensory function. The carapace has a nuchal bone, which is a bone over the area in which the head and neck are retracted, and it has riblike processes extending from both sides. Only Sternotherus odoratus, the Eastern Musk Turtle, sometimes called the “stinkpot,” occurs in Michigan.

Sternotherus odoratus (Latreille 1801) Eastern Musk Turtle Identification The Eastern Musk Turtle is a small, mainly dark-colored, large-headed, bottom-walking turtle with a narrow and highly arched black or brownish black carapace that may be covered with algae. The snout is pointed. Two bright yellow stripes occur on either side of the head, except in old males, on which they may be obscure. Two stripes also occur on either side of the neck, but these are usually not as prominent as the head stripes and may be somewhat interrupted. The plastron is small and displays some skin between the scutes, especially near the center. The front of the plastron is flexible but does not offer much closure for the turtle. Sensory barbels occur on the chin and throat. The male is easily distinguished from the female by its longer, thicker tail that ends in a blunt spine. The adult carapace length in Michigan ranges from about 83 to 136 mm (3.27–5.35 in.). General Distribution Eastern Musk Turtles range from southern Maine and southeastern Ontario, Canada, south through

Pennsylvania to Florida, west to central Texas, and north to the southern part of Wisconsin. These turtles do not generally occur in high elevations within this range. Michigan Distribution Musk Turtles are absent from the Upper Peninsula and Michigan islands. They are widespread in roughly the lower half of the Lower Peninsula, extending north to Newaygo County in the west. There are no records for this species in the northern thumb area, or the counties surrounding Sagninaw Bay. A record from Montmorency County in the northeast part of the Lower Peninsula may represent a relict population, but more information is needed from the area. Geographic Variation No distinct variant populations of Sternotherus odoratus have been recognized in Michigan. Moreover, no subspecies are presently recognized in this species. Differences have been noted in S. odoratus, however, which may lead to the naming of subspecies in the future. For example, Ernst and Lovich (2009) have reported that Sternotherus odoratus in Florida are shorter and darker than those that occur in more northern areas. Habitat and Habits Within its large range, the Eastern Musk Turtle occurs in quite a variety of habitats. Ernst and Lovich (2009) state that this species occurs in almost any aquatic situation that has a slow current and soft bottom. This includes rivers, streams, lakes, ponds, sloughs, canals, swamps, bayous, and oxbows. In Michigan, a favorite habitat is the shallows of lakes with marl, sand, or gravel bottoms. Lagler (1943, 259) stated that “in Michigan I have collected it [S. odoratus] most commonly in those portions of lakes, or lagoon-like sections of rivers, where aquatic vegetation grows abundantly but not so densely as to impede greatly the movements of the turtles on the bottom. Particularly favorable environments were the reedy, firm-bottomed areas as such lakes as Whitmore [Washtenaw County], Sherman [Kalamazoo County] and Wolf [Van Buren County].” I have observed the turtles of the muck-bottomed bog lakes in the Lansing, Michigan area for many years, but I have never found Musk Turtles in any of them. There is, though, a record of this species from an ancient

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FIG. 75. Eastern Musk Turtle (Sternotherus odoratus) from Barry County, Michigan. Photograph by the author.

peat bog in the Lansing area, and it is discussed later in the Holocene section of this book. Minton (2001) stated that S. odoratus in Indiana avoids peat bogs. The main activity of Eastern Musk Turtles is crawling on the bottom of the aquatic situation in which they live. They do this mainly at night; during the day this species usually buries itself in the substrate or rests on the bottom (Ernst 1986). Lagler (1943, 259) recorded that “although individuals were seen foraging at all hours of the day, they appeared to be more active at night.” The basking habit is poorly developed in Musk Turtles, although on a few occasions I have seen single individuals on top of brush piles or the extended limbs of fallen trees in northern Indiana. These animals were basking well above the water on their perches, one individual resting on a branch several feet above the water. These turtles did not appear to be particularly wary. Risley (1933) described seeing two S. odoratus in Michigan basking under these conditions and that both of them were on fallen trees in the Huron River. He also stated that when members of this species rest or sun themselves they usually do so without leaving the water; they are often found floating motionless on the surface with only the top of the carapace showing. Eastern Musk Turtles apparently have a long period of activity in Michigan. Risley (1933) collected them on March 25, 1928, and March 23, 1929. Lagler (1943) collected them as late as October. Risley reported

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that the young animals made their appearance later than the adults, coming out of hibernation near the first of May. Musk Turtles hibernate in a variety of situations. Ernst and Lovich (2009) reported that these turtles bury themselves underwater in the mud; beneath logs, rocks, or detritus near the water; in muskrat dens or lodges; or in recessions under banks. They dig in when the water temperature falls to 10ºC (50ºF). Ernst (1986) reported that the mean home range of male Musk Turtles in Pennsylvania is 1.75 ha (4.32 acres) and of females .94 ha (2.32 acres). Williams (1952) studied the homing of S. odoratus in a southern Michigan lake and found that fifteen of fifty turtles came back to the proximity of their original capture. One individual returned to within 15 m (49.2 ft.) of its original capture point eight times. The turtle’s route consisted of straight-line movements of at least 213 m (698.6 ft.) from the site where the turtle was released. Musk Turtles have color vision (Ernst et al. 1970) and chose red or yellow colors over green or blue (Ernst and Hamilton 1969). This research led to the speculation that S. odoratus color detection abilities might aid in the movement and directional orientation of the turtles. Lehr and Rowe (2005) placed radiotransmitters on the rear margin of the carapaces of six Sternotherus odoratus individuals at Brewster Lake in southwestern Michigan and followed their movements. They found that these turtles concentrated their activities along the margins

2. Species Accounts

of the lake below 1 m (3.28 ft.) and rarely entered the deeper waters near the center of this small lake. One of the turtles left the lake and entered a creek system where it concentrated its movements for the rest of the summer; the other individuals moved into shallow, flooded areas bordering the lake. These turtles were active throughout the day, including late evening and early morning. Reproduction and Growth Risley (1933) wrote that it took female Musk Turtles in Michigan nine to eleven years to reach sexual maturity, but Tinkle (1961) stated that females of this species reach sexual maturity in two to seven years when their length exceeds 80 mm (3.15 in.). In the Great Lakes region, mating occurs in the water, mainly in April and May, although it may occur again in the fall (Harding 1997). A sexually aroused male Musk Turtle chases the female, at the same time nudging or nipping at her head and the edges of her carapace. If the female is receptive to his advances she slows down enough to let herself be caught. The male then crawls on top of her and holds on to her carapace with the claws of all four feet. The male has patches of scales on the inner side of his hind legs, which can hold the tail of the female while his tail curls around hers. The spinelike tip of the male’s tail facilitates vent-to-vent contact for insertion of his penis. The time elapsed between mounting and penis insertion may be short, sometimes only a few seconds. Nesting usually takes place in the Great Lakes region between late May and July. Sometimes Musk Turtles excavate nests with their hind legs in a manner similar to that of other Michigan turtles. Newman (1906), however, watched a female dig with her snout as well as all four feet. A female may simply put her eggs on the soil under logs, vegetation, or organic debris near the shoreline, or even in the top of a rotten stump. Sometimes the eggs are not even completely covered. Harding (1997) remarked that Musk Turtles in the Great Lakes region usually lay a single clutch of eggs each year. Usually about three to five eggs are laid in a clutch (the range is one to thirteen). The eggs are elliptical in shape and are from about 23 to 31 mm (0.91–1.22 in.) in length. These eggs have rigid but brittle shells that tend to give the embryos extra protection from drying out, probably a necessity considering their frequent shallow burial.

In Pennsylvania, hatching success of 104 eggs in more than thirty-two nests was only 15.4 percent. Considering other factors reducing survival, particularly predation, it was estimated that the survival potential was about 0.5 egg per clutch (Ernst 1986). The incubation period ranges from about sixty-five to eighty-five days, and the hatchlings emerge from August to November, depending on the geographical latitude and local conditions. The hatchlings are tiny—just 18.5 to 22.8 mm (.73–.90 in.) in carapace length—and according to Minton (1972) they resemble blackened nuts or bits of driftwood. Risley (1933), from an eight-year growth study of S. odoratus in Michigan, reported that these turtles grew by about the following average increases per year, beginning with their hatching: 32.5 mm (1.28 in.), 52.0 mm (2.05 in.), 61.0 mm (2.40 in.), 67.0 mm (2.64 in.), 71.0 mm (2.80 in.), 74.5 mm (2.93 in.), 77.6 mm (3.06 in.), and 80.0 mm (3.15 in.). Diet Lagler (1943) examined the stomachs and colons of 113 S. oderatus from a variety of lakes and rivers in Michigan. The only fishes in the stomach contents were taken as carrion. He found that more fish carrion was consumed by these turtles in July when more game fish are killed (e.g., by deep hooking) than later on in the summer. The frequency of occurrence of food items in the turtle stomachs was as follows: Percentage Food Insects 34.2 Snails and clams 28.3 Plants 15.0 Vegetable debris 12.5 Carrion 5.8 Crayfishes 3.3 Game and pan fishes 0.8 Unidentified fishes 0 In composition by volume, the three highest percentages of food were carrion, 40.1 percent; snails and clams, 23.2 percent; and insects, 16.9 percent. Harding and Holman (1997) reported that in Michigan this species eats a wide assortment of food and always feeds underwater. The food items include insects, crayfishes, snails, worms, tadpoles, and aquatic plants.

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Unfortunately, Musk Turtles take the hooks of anglers now and then, especially if they are baited with worms. Sometimes the turtles get their heads cut off for doing this. Actually, the hook is usually easily removed, if the fisher will take the time and effort, and the turtle can be released and return to cleaning up the carrion in the lake. Predation and Defense Musk Turtle eggs are eaten by snakes (Kingsnakes and Scarlet Snakes), skunks, raccoons, and various herons and crows (Ernst and Lovich 2009). Harding (1997) reported that in the Great Lakes region, crows, rodents, raccoons, and skunks eat the eggs and that hatchlings and juveniles are preyed upon by predatory fishes such as bass and pickerel as well as large frogs, watersnakes, and herons. Raccoons, otters, mink, and bald eagles eat both juveniles and adults, and muskrats will attack hibernating turtles in the winter. Musk Turtles are not infrequently seen crossing roads in Michigan, and I have seen cars run over them. Some drivers appear to be unaware they have run over anything, especially if these darkly colored animals are on blacktop roads. On the defensive side, these turtles secrete a strong musky substance from glands under the carapace rim near the bridge, and this odor may ward off some kinds of predators. From handling this species for many years across many parts of its range, I have found that picking up the adults usually elicits one of three behaviors: (1) vigorous biting attempts and thrashing of the legs; (2) the withdrawal of the head and legs but with the mouth held wide open (but the jaws snap shut if touched); or (3) the withdrawal of the head and legs with the mouth closed, and biting or gaping does not occur even when the turtle’s nose is touched. Interaction with Humans I am not aware that humans have ever eaten Musk Turtles, although people have swallowed stranger items (e.g., salamanders with toxic skins). I am also not aware that these animals have been commercially collected for biology labs, although I have seen them on pet trade lists a few times. Harding (1997) suggested that residential shoreline development, which often results in the removal of aquatic plants from shallow-water areas to enhance swimming and boating, and the loss of terrestrial nesting areas are probably the most serious threats to Sternotherus odoratus.

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Behavioral Characteristics For the behavioral characteristics of Eastern Musk Turtles, see the sections “Habitat and Habits,” “Reproduction and Growth,” and “Predation and Defense” in this account. Population Health Sternotherus odoratus is not on the Threatened or Endangered lists in Michigan, and as long as relatively clean lakes with sufficient natural vegetation are available in southern Michigan, these little turtles should persist. General Remarks Eastern Musk Turtles are really quaint little animals. I can picture so well this little turtle scrambling with all four of its stumpy little legs and its nose to dig a makeshift nest before it or its eggs are found by a predator. I detest the oft-used name “stinkpot” and cringe every time I see it. As far back as Risley (1933), the common name recorded for this turtle was “Common Musk Turtle,” a name that it had for many years (now Eastern Musk Turtle). Risley reported that in some localities this turtle is known as “stink-pot terrapin” and in others as “little snappers” (685). I see no use in giving any harmless animal a common name that will cause it to be subject to human abuse. Several kinds of mammals smell musky (including humans at times), but they are not officially registered anywhere as “stinkpots.”

Family Trionychidae The Family Trionychidae is a group of aquatic turtles whose members are characterized by a soft, flexible shell lacking horny scutes. Softshell turtles occur today in Africa, Asia, the Indo-Australian archipelago, and North America. Fossils of this family date back to the Jurassic, when dinosaurs were at the apex of their abundance, and great aquatic reptiles ruled the seas. Five species of softshells live in the United States (and one of these also occurs in Canada). Two of the United States species occur only in Hawaii and were introduced there from Asia. The necks of softshells are very long, and the snout usually consists of a long proboscis that functions as a snorkel. The limbs are paddle-like with three claws on each limb. Softshells are better swimmers than some fishes. Bones are present in the shells of softshells but

2. Species Accounts

are very reduced and do not encumber the swimming skills of this family. The vertebrae in the necks of these turtles are slender, and the skull has widely open cavities in the back as well as other specializations. The Family Trionychidae is divided into two subfamilies, and all the United States species belong in the subfamily Trionychinae.

in roughly the southern third of the Lower Peninsula, where it ranges north to Newaygo County in the western part of the state and to Saginaw Bay in the east. The Eastern Spiny Softshell, however, is also known from two counties, Grand Traverse and Crawford, in the northern part of the Lower Peninsula. It seems possible that these records represent relict populations.

Apalone spinifera spinifera (Lesueur 1827) Eastern Spiny Softshell Identification The Eastern Spiny Softshell is undoubtedly the oddestlooking turtle in Michigan. It has a flattened pancake-shaped shell, a very long neck, and a snorkel for a snout. Both the carapace and plastron lack epidermal scutes, and the bones are well hidden under a soft, rubbery shell that has flexible edges. The carapace of this turtle is tan, olive, or brown, and bears black spots, flecks, and circles in hatchlings, juveniles, and adult males. Adult females, on the other hand, become dark, blotched, or mottled with gray or brown. The color of the plastron is white or pale yellow, and the bones beneath it are visible as gray patches. All four feet of this turtle are fully webbed. The side of the head is usually marked with two yellow stripes edged in black. In the Great Lakes region, the adult female carapace length ranges between 240 and 480 mm (9.4–18.9 in.) and the adult male carapace ranges from 127 to 240 mm (5.0–9.4 in.). General Distribution The subspecies Apalone spinifera spinifera subspecies ranges from western New York through the southern portion of the Great Lakes region to central Minnesota, south to the northern borders of Mississippi and Alabama, and eastward to extreme western Virginia and western Pennsylvania. Isolated populations occur in New Jersey, eastern New York, northwestern Vermont, and adjacent Quebec, Canada. The Eastern Spiny Softshell intergrades with other subspecies of Apalone spinifera that occur south and west of its range (Minton 2001). Michigan Distribution The Eastern Spiny Softshell is absent from the Upper Peninsula and the islands of Michigan. It is widespread

Fig. 76. Juvenile Eastern Spiny Softshell (Apalone spinifera spinifera) from Michigan. Photograph by James H. Harding.

Habitat and Habits In Michigan this highly aquatic turtle prefers to inhabit larger streams and rivers, where it can often be seen sunning itself on the muddy banks and sandbars. It also inhabits inland lakes, reservoirs, and even the protected bays and river mouths of the Great Lakes (Harding 1997). I was surprised to find some in a bog lake in northern Jackson County in southern Michigan. Ernst and Lovich (2009) stated that a soft bottom with some aquatic vegetation seems to be essential for this species, but I have found this not always to be the case because I have seen them in southern Michigan streams whose beds are mainly rocky, pebbly, and sandy with glacial boulders emerging from place to place. On the other hand, these streams did always have sandbars here and there too. In south-central Indiana I have seen these turtles in creeks whose beds were composed mainly of large slabs of shale, but again sandbars also occurred from place to place. The Eastern Spiny Softshell, like the Northern Map Turtle, can tolerate certain types of pollution fairly well.

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This animal has been relatively common in the Red Cedar River both on and off the Michigan State University campus, including during the 1960s when the river was highly polluted. Although the population seems to have declined in numbers, all sizes of individuals are still present today. The adults are quite wary as they bask facing the water on sand and mud banks; they slide into the water the moment they are disturbed. The juvenile Eastern Spiny Softshells are less wary, and the hatchlings are least wary of all; sometimes juveniles may be easily picked up when they are basking. Nesting sites may be limiting for this population, as the open sandbanks preferred for nesting have largely disappeared in the vicinity of the campus. During the warmer months, the daily activity of Eastern Spiny Softshells in Michigan consists of basking, foraging, and then resting or lying in wait for prey in shallow water in the sand, silt, or mud in which they bury themselves. They can remain buried for long periods of time by extracting dissolved oxygen from the water. This is partially accomplished by pumping oxygenated water over the vascularized (well supplied with blood vessels) lining of their throat by expanding the neck. Moreover, the lining of their cloaca (a pocket where both reproductive and waste products pass through on the way to the vent) and various areas of their skin are highly vascularized as well. Dunson (1960) showed that either skin or cloacal respiration could sustain life for up to five hours of forced submersion in softshells. In the Great Lakes region and Michigan, Eastern Spiny Softshells often hibernate earlier and become active later in the spring than most other turtles in the region. They are largely dormant from early October to April or even May (Harding 1997). They spend this period of dormancy buried in bottom sediments. Reproduction and Growth Unfortunately, very little is known about the mating habits of softshell turtles, probably because mating occurs in relatively deep water (Minton 2001). Regarding the Great Lakes region, Harding (1997) stated that Eastern Spiny Softshells mate in April and May. The male swims alongside the female and nudges her head and shell. This may be to sexually stimulate her or perhaps to determine her willingness to mate. Supposedly during mating the male swims just above the

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carapace of the female rather than holding her tightly with his claws. All of this needs to be confirmed by observations in nature, and much more information is needed regarding the mating habits of Eastern Spiny Softshells both in the Great Lakes region and elsewhere. Female Eastern Spiny Softshells nest in June or early July in the Great Lakes region and Michigan. They often nest in the morning on sunny days. Unlike many turtles that seem to take their time finding a nesting site, digging the nest, and then covering the eggs, nesting is a hurried process for Eastern Spiny Softshells and may occur within an hour or less (Harding 1997). The female digs the nest cavity with her hind feet, and it ranges from 90 to 250 mm (3.5–9.8 in.) in depth and from 76 to 128 mm (3–5 in.) in diameter. Nine to thirty-eight eggs are laid. The eggs are round and have a hard, limey shell. Larger females lay larger eggs. Unlike most other turtles in Michigan, Eastern Spiny Softshells do not have temperature-dependent sex determination (TSD) (Bull and Vogt 1979; Jansen and Paukstis 1991). Sex ratios are essentially 1:1 under a wide range of temperatures, which suggests that sex determination is chromosomal rather than environmental (Ernst and Lovich 2009). Hatchlings look like miniature adult males, with a rounded pale olive or tan carapace that is marked with a pattern of small dark circles, spots, or dashes and a yellow border emphasized by a black line. These hatchlings range in carapace length from 30 to 40 mm (1.18–1.57 in.). Diet Lagler (1943) in Michigan and Newman (1906) in northern Indiana watched Eastern Spiny Softshell turtles crawling or swimming along the bottom of lakes, pushing their snouts under stones and into masses of aquatic vegetation, and snapping up a crayfish or insect larva that they had dislodged. Lagler (1943) studied the food habits of this animal. The frequency of food items in eleven softshell stomachs was as follows: Food Insects Crayfishes Vegetable debris Lower plants Snails Fish remains

Percentage 90.9 45.5 27.35 9.1 9.1 1.9

2. Species Accounts

The importance of crayfish and insects in the diet of this turtle has been emphasized by other researchers, including Newman (1906), Surface (1908), and Evermann and Clark (1920). Webb (1962) reported that the Eastern Spiny Softshell is mainly carnivorous, and crayfish and insects form the main part of its diet. Some plant material is also regularly eaten but may be ingested incidentally to the taking of animal prey. Predation and Defense Many Great Lakes region Eastern Spiny Softshell nests, if not most of them, are destroyed by raccoons, skunks, foxes, and other mammal predators, according to Harding (1997). The hatchlings and juveniles are vulnerable to raccoons, herons, and large fishes. The adults appear to have few predators except for humans. Ernst and Lovich (2009) reported that many softshells are decapitated by anglers after being hooked. The rapid swimming ability and lightning-fast strike of its sharp jaws when confronted doubtlessly contributes to the survival of softshell turtles, especially the large adults. Interaction with Humans As far as I am aware, Eastern Spiny Softshells are not frequently used for food in Michigan. I am guessing this is at least in part because they are less common, have much less usable meat, and are far more elusive than the Eastern Snapping Turtle. Softshells are rarely, if ever, commercially collected as animals to be dissected in biology or zoology classes. As explained in the diet section of this account, Michigan softshells are not a direct threat to the game fishes in the state. They probably do compete in a secondary way with game fish and other fishes because of their fondness for crayfishes and insects. Probably because of their intake of dissolved oxygen underwater, these turtles can be killed or made very sick by the chemical rotenone that is sometimes used to remove unwanted fish species from lakes and streams. I once witnessed a beaver pond being treated by rotenone in a study in the panhandle of northern Florida in 1956. Softshells rose to the top of the water in obvious distress while others just below the surface swam about frantically. I don’t know whether these poor creatures lived or died. In Michigan, threats to this species include chemical pollutants, shoreline development that

eliminates areas critical for nesting sites, injuries from boat propellers, and being shot by “plinkers” (vandals with .22-caliber rifles). Population Health Softshell turtles are considered Endangered or Threatened in Michigan. If the waterways of the state are kept relatively clean, and people can be educated about how to manage their shorelines, the present populations should be able to maintain themselves. General Remarks Much remains to be learned about the breeding habits of the Eastern Spiny Softshell. Biologically oriented scuba divers, it seems, could endear themselves to the herpetological community by swimming among these coupling creatures with cameras.

Order Squamata The Order Squamata contains both the lizards and snakes. Squamata forms the most diverse group of reptiles that are living today. About 4,460 lizard species and about 2,900 snake species are recognized at present, and more are being named seemingly on a daily basis (Vitt and Caldwell 2009). All squamates have specially hinged jaws that are not found in other groups of reptiles, as well as paired, eversible copulatory organs (hemipenes) at the base of their tails. The forked tongue of some lizards and snakes picks up certain chemical scents from the environment and transfers these to the Jacobson’s (or vomeronasal) organ in the roof of the mouth where the chemical signal is processed and sent to the brain. Most herpetologists consider snakes to be a highly specialized group of lizards, but which lizard group represents the closest relative of the snakes is still unsettled. All living snakes and some living lizards have lost their limbs, and all of them are covered with small scales or derivatives thereof. Squamate history can be followed back about 220 million years to the late Triassic, but determining the identity of the direct ancestors of lizards (and snakes) is still a matter of ongoing research. Squamates occur worldwide except in very cold areas. Both are more numerous in the tropics than they are in temperate or moderately cold regions. Michigan has only two lizards: one has such an exceedingly limited

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range in the state that it is thought by some to represent an introduced species; the other is rather widespread and occurs in both peninsulas. Eighteen species of snakes occur in Michigan, a rather surprising number to some. Only one of these species, the Eastern Massasauga (a rattlesnake) is venomous. Like the turtles, some of the snakes in Michigan are rare and need protection. Other snakes that were once thought to be abundant are now reduced in numbers. Fortunately, a few snakes are still common in Michigan, but even these need to be carefully monitored.

Lizards Family Scincidae As a group, skinks are characterized by smooth, shiny, rounded scales that are underlain by bones, each one of which is made up of a mosaic of tiny bony parts rather than a single bone as in other lizards. Many skinks also have a secondary palate lying under the primary palate, an unusual situation in lizards. Skinks are variable in body form. Some are similar to typical lizards, having stout limbs and short bodies. Others have long, snakelike bodies with tiny limbs. Still others have very elongated bodies without limbs. Some skinks occur in relatively cold temperate areas like Michigan, but others live in the warm tropics, and at least one species lives in shallow seas and feeds on small invertebrates called sand fleas. Skinks are worldwide in their distribution except for very cold areas. Only one skink, the Five-lined Skink (Plestiodon fasciatus) lives in Michigan.

Plestiodon fasciatus (Linnaeus 1758) Five-lined Skink Identification The Five-lined Skink is a small shiny lizard with smooth scales. The juveniles of this species have five yellowish or whitish stripes running from the top and side of the head down the back to about halfway down the tail. The rest of the tail is blue. The overall background color is black in the juveniles and some shade of brown in the adults. The blue tail disappears in the adults, and the stripes on the males usually fade or sometimes completely disappear. During the spring breeding season, a significant portion of the male

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head becomes a reddish orange color. This color may be retained on the lips and chin throughout the year. Adult lengths range from 127 to 203 mm (5–8 in.) (Harding and Holman 1990). General Distribution This lizard occurs from eastern New York southward to northern Florida and west to Wisconsin, Missouri, and the eastern part of Kansas, Oklahoma, and Texas. Disjunct populations occur in west-central Minnesota, northeastern Iowa, and adjacent portions of southern Minnesota and Wisconsin. Within the Great Lakes basin, this skink occurs in southern Ontario, Ohio, Indiana, the Lower Peninsula of Michigan, and the central part of Michigan’s Upper Peninsula (Harding 1997). Michigan Distribution Plestiodon fasciatus occurs in the central part of the Upper Peninsula in Marquette, Alger, Dickinson, Menominee, and Delta counties. It is absent from Michigan islands. This lizard is widespread in the upper half of the Lower Peninsula, except that it has not been recorded in the northwestern row of counties bordering Lake Michigan, namely Leelanau, Antrim, Charlevois, and Emmet. The occurrence of Five-lined Skinks is very spotty in the bottom half of the Lower Peninsula, the only confirmed cluster of counties where this species has been recorded being Ingham, Oakland, Washtenaw, Wayne, Monroe, and St. Clair in the southeastern part of the state. More surveys are needed to determine the distribution of this species in the southern half of the Lower Peninsula. Geographic Variation No distinct populations or subspecies of this skink have been recognized in Michigan or elsewhere, but it would be interesting to know whether significant genetic differences exist between the Upper Peninsula populations, which presumably invaded Michigan from Wisconsin, and those in the Lower Peninsula, which must have entered the state from Indiana and Ohio. Habitat and Habits Five-lined Skinks are woodland lizards that prefer forest edges and openings where logs, stumps, and other such structures present shelter and basking perches.

2. Species Accounts

to 34ºC (82.4–93.2ºF), which is their preferred level for activity. They may forage and breed at temperatures somewhat lower than these but not much higher (Harding 1997). In the Great Lakes region these lizards become dormant between early October and late April or early May. They hibernate in such places as stumps or logs, rock crevices, foundations of buildings, or piles of vegetation. Minton (2001) reported that in Indiana, Plestiodon fasciatus has been seen as early as March 26 but that adults are most often first noticed in May or June.

Fig. 77. Juvenile Five-lined Skink (Plestiodon fasciatus) from Allegan County, Michigan. Photograph by James H. Harding.

These skinks appear to be at home in either moist or dry woods in Michigan, as long as the situation is not too dry. Harding (1997) noted that populations of these skinks are sometimes found in woody debris along sandy Great Lakes beaches. Ruthven (1911, 263–64) gave a detailed account of this lizard in the sandy habitats of Huron County at the tip of the thumb area in Michigan: “In the woods of the sand region it [the skink] was found on the dry ridges, under and in decaying logs, where it fed on the insects that frequent such situations. It was, however, much more common than elsewhere under the drift logs on the fossil beaches, and also on the middle beach of the present shore, at the extremity of Sand Point. The logs strewn along the fossil beaches were in an advanced stage of decay, and usually consisted of an outer shell of better preserved wood covering a mass of decomposed debris, the decomposition taking place most rapidly near the ground. This apparently furnished a very favorable habitat for these lizards, great numbers of which were found in the decomposed material when the log had been removed.” Michigan skinks are not highly arboreal, but they sometimes climb onto tree trunks or stumps to bask or hunt for food. Minton (2001) reported that these lizards have a tolerance for both shade and moisture. This is unusual compared to many species of lizards in North America. Harding (1997) reported that Plestiodon fasciatus in the Great Lakes region stays within small home ranges about 9 to 30 m (29.5–98.4 ft.) in diameter. These lizards bask to raise their body temperature to about 28

Reproduction and Growth Male Five-lined Skinks defend a territory during the spring breeding season, but they will allow the presence of both females and juveniles during this period. C. H. Pope (1944, 158) stated that “males sometimes attack one another with great vigor, the ensuing battle being real tests of strength and endurance, in which bluffing, so commonly evident in the aggressive behavior of many other lizards, plays no part. The male’s wide head and powerful jaws are correlated with this genuine fighting.” Harding (1997, 232) stated that “it is likely that potential mates and rivals are recognized in at least two ways—by chemical cues picked up by the flicking tongue and transferred to the vomeronasal organ, and by the presence or absence of the bluish tail color (in females) and reddish jaw color (in males).” When a Five-lined Skink is ready to mate, he will approach a female from the side, turning his head at a sharp angle so he can grasp her neck just behind the ear opening. When he secures a firm grip, he throws his nearest two limbs over her back and wraps his tail around hers to align their cloacal openings. This allows him to insert one of his two hemipenes and copulate, which lasts from about four to eight minutes (C. H. Pope 1944; Harding 1997). The female lays eggs at least a month after copulation at a nest site in a rotting stump, beneath loose bark, inside a small mammal burrow, or under a rock. She first clears away debris to create a small cavity and then lays from five to eighteen thin-shelled eggs that tend to vary in shape from round to oval. The tiny eggs are about 13 mm (0.51 in.) in length. The brooding habits of female Plestiodon fasciatus are very well developed and have been commented on by various authors (e.g., Ruthven 1911; Noble and Mason 1933; C. H. Pope 1944; Fitch 1954; Harding and

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Holman 1997; and Minton 2001). The female behaviors in this situation include the following: 1. Curling her body around the eggs and always keeping her body in contact with some of them. 2. Leaving the nest from time to time to feed and also to bask to raise her temperature for incubation purposes. 3. Turning the eggs with her tongue and snout. 4. Forcefully attacking and biting intruders such as shrews, mice, other reptiles, or human fingers. 5. Gathering scattered eggs back together again, by taking them in her mouth and carrying them, by pushing them with her nose, or by rolling them in the curve of her body. 6. Keeping the eggs properly moist by urinating on them. 7. Eating eggs that spoil. 8. Continuing to protect hatchlings until they leave the nest. Diet In the Great Lakes region, Five-lined Skinks feed mainly on invertebrates such as termites, millipedes, spiders, crickets, beetles and their larvae, caterpillars, and snails. Large males, with their strong jaws, may eat smaller reptiles and even newborn mice. James C. Gillingham (pers. comm.) has observed Five-lined Skinks feeding on berries in the central part of the Lower Peninsula, and Harding (1997) stated that captive skinks have been observed to eat berries and that it is possible wild ones might do so as well. Minton (2001, 236) described watching some Five-lined Skinks feeding: “While hand sawing some old logs, I saw several of these skinks emerge to feed on beetle larvae and other insects dislodged by my activity. If the prey was large, it was shaken and chewed until it could be swallowed.” Fitch (1954) reported that these Five-lined Skinks eat their own shed skins and that on rare occasions they eat their own hatchlings. Predation and Defense Fitch (1954) claimed that the short-tailed shrew (Blarina brevicauda) is one of the most important enemies of Five-lined Skinks. Other enemies of this lizard include snakes of several species, moles, opossums, skunks, house cats, and hawks. On the defensive side, male skinks can

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bite at their predators with their strong jaws. C. H. Pope (1944, 157) stated that “when seized, the tail breaks off easily, an event that doubtless confounds an enemy and often allows the skink to make its escape while the predator is struggling with the violently wriggling appendage. A new tail soon grows out of the stump of the old one.” Vitt and Cooper (1986) reported that the negative implications of tail loss in Plestiodon fasciatus are offset by the increased probability of escape from predators. Interaction with Humans The Five-lined Skink graces the Michigan woodlands with its bright colors and interesting behavioral characteristics. In places where this lizard is abundant, it may help with insect control. Selective logging can open forest canopy and leave stumps, bark slabs, and sawdust piles that benefit this lizard; however, the clearing of forests or removal of dead logs or wood and beach debris is harmful to them (Harding 1997). Minton (2001) mentioned that in Indiana the orange-headed males of Plestiodon fasciatus are called scorpions and that their bite is said to produce a gangrenous sore. I am not aware of any such alternative name being used in Michigan. Behavioral Characteristics For the behavioral characteristics of the Five-lined Skink, see the sections “Habitat and Habits,” “Reproduction and Growth,” “Diet,” and “Predation and Defense” in this account. Population Health The Five-lined Skink is not on the Threatened or Endangered lists in Michigan. The generally spotty distribution and lack of records in much of the southern part of the Lower Peninsula is curious, and these areas should be systematically searched for evidence of this species. General Remarks More extended field observations of skinks in Michigan are needed. It would be interesting to know, for instance, how frequent or widespread is the habit of eating berries in this species in Michigan because most all small lizards are carnivorous, eating mainly insects and other small invertebrates.

2. Species Accounts

Family Teiidae The Family Teiidae is composed of two groups of lizards referred to as the microteiids and macroteiids (small and large teiids). Some herpetologists consider these two groups to be separate families. Defining this family on the basis of unique characteristics is difficult, but most of the members share the following attributes: 1. They are generally very active diurnal (daytime) lizards. 2. They are all oviparous (egg-laying). 3. Communal nesting is not rare in the group. 4. Parthenogenesis (virgin birth) is prevalent in some microteiid genera, including species of the genus that occurs in Michigan. Members of this family range in size from small, limbless species to animals that may reach a total length of 1 to 1.3 meters (3.28–4.26 ft.). This family occupies many types of habitats ranging from arid deserts to rain forests. The Teiidae occur from the northern United States through Central America and the greater part of South America. The only member of this family that occurs in Michigan is the Six-lined Racerunner (Aspidoscelis sexlineata), a microteiid that occurs only in Tuscola County in the thumb area.

Aspidoscelis sexlineata (Linnaeus 1766) Six-lined Racerunner NOTE: The Six-lined Racerunner had the scientific name Cnemidophorus sexlineatus for many years, but it was recently changed (Crother 2008). Identification The Six-lined Racerunner has a lined body like the Five-lined Skink described in the preceding account, but it has six or seven rather than five lines and is in many ways quite different from that species. Aspidoscelis sexlineata is a slim, long-tailed lizard that can run very quickly in short bursts. Six yellowish green or whitish stripes extend down the back and sides. The overall color between the stripes may tend toward black, gray, brown, or olive. In the adult animals, the neck and forward parts of the body may be a shade of green or blue-green. The scales on the body are granular (like tiny bumps), but the scales on the head are large and platelike.

Underneath, the scales of the belly are flat, rectangular, and arranged in rows. Rings of rough scales encircle the tail. The total length of this lizard averages about 260 mm (10.24 in.), and its snout-to-vent length averages about 85 mm (3.35 in.).

Fig. 78. Six-lined Racerunner (Aspidoscelis sexlineata) from Indiana. Photograph by James H. Harding.

General Distribution This lizard occurs from Maryland to the Florida Keys, westward to extreme southern Texas, north to extreme southern Wyoming and southern South Dakota, and in the Mississippi River valley as far as southwestern Minnesota and adjacent Wisconsin (Minton 2001). Michigan Distribution In Michigan, the Six-lined Racerunner occurs in a single thriving but isolated population in Tuscola County in the thumb area (Yoder 2007). Geographic Variation The Six-lined Racerunner is divided into three subspecies: the Eastern Six-lined Racerunner (A. s. sexlineata), Texas Yellow-headed Racerunner (A. s. stephensae Trauth 1992), and Prairie Racerunner (A. s. viridis ) (Crother 2008). The greenish color on the head of male specimens and the presence of seven or eight dorsal stripes in the Michigan population of Racerunners would agree most closely with the Prairie Racerunner (J. C. Gillingham, pers. comm., 2004; Yoder 2007).

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Habitat and Habits In general, the preferred habitat for the Six-lined Racerunner is open grassland and woodlands with occasional bushes and marginal thickets; usually the soil is well drained and sandy (Bellis 1964; Clark 1976). The Tuscola County, Michigan, population occurs in a relatively open area that slopes downward from the edge of a coniferous forest. The upper part lacks significant ground cover, the middle area has clumps of vegetation, and the bottom area is primarily open sand (Gillingham et al. [1990?]). The Six-lined Racerunner is locally abundant in northwestern Indiana, where it occurs from the Lake Michigan Dunes and sand prairies east to Winamac in Pulaski County; it occurs in an isolated population in Tippecanoe County too. This species also occurs in southwestern Indiana, but it has not been found in the area in between (Minton 2001). Minton also reported that this lizard is gregarious, living in colonies, and is sun-loving and almost continually moving about during its activity period. Racerunners do not normally climb. Reproduction and Growth In the Great Lakes region, courtship and mating begin in May or early June. Breeding males display their colors and establish well-developed dominance hierarchies. Dominant males chase all others in a despotic fashion in an effort to mate with females (Carpenter 1960, 1962). Following a brief courtship, the female is straddled and bitten on the neck by the male, which eventually grasps her neck area with his jaws. He then turns his tail under hers until the vents come together and one of his hemipenes is inserted (Harding 1997). The female lays from two to eight eggs in June in a burrow 80 to 300 mm (3.1–11.8 in.) deep. The eggs are oval with thin, flexible shells and are about 17 mm (0.67 in.) long. Incubation lasts about two months, with the eggs hatching in August or September. The young become sexually mature in their first or second year. Diet The diet of juvenile Racerunners studied in the Tuscola County, Michigan, population consisted of beetles, 30 percent; homopterous insects, 38 percent; snails and spiders, 22 percent; with the remaining 10 percent of their diet consisting of other insects and crickets. The general

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diet of Racerunners in the Great Lakes region consists of spiders, snails, beetles, flies, plant hoppers, crickets, grasshoppers, and moths (Harding 1997). In Indiana Minton (2001) observed Racerunners actively catching moths, small crickets, caterpillars, and small wasps. Predation and Defense In the Great Lakes region, snakes (e.g., Racers, Milksnakes), birds, and small mammals prey upon Racerunners. The best defense this species has is making a quick dash to the nearest burrow or other cover. Racerunners are apt to lose their tails when grabbed by predators, but their tails are not as easily shed as those of the skinks. Minton (2001) reported that he has seen Indiana specimens jump from one ledge to another several feet below. He also has seen these lizards jump into water and hide under submerged debris when pursued. Interaction with Humans In general, the interactions of this species with humans are passive. In Michigan, they have been seen by very few people. If anyone finds another colony of these lizards in the state, the find should be reported to the MDNR and the Michigan Natural Features Inventory. Behavioral Characteristics For the behavioral characteristics of the Six-lined Racerunner, see the sections “Habitat and Habits,” “Reproduction and Growth,” “Diet,” and “Predation and Defense.” Population Health This population of lizards has been thriving in Tuscola County for at least thirty-five years, which has warranted the classification of this animal as (at least) a naturalized species for the state of Michigan. It is listed as a Species of Special Concern and is protected in the state. Even though this population is relatively small, it appears to be doing well biologically (Yoder 2007). General Remarks Although considerable field work has been done on this Michigan Racerunner population (Gillingham et al. [1990?]; Yoder 2007), the data have not yet answered the question of the origin of this species in Michigan. The

2. Species Accounts

field researchers have proposed that one or the other of two hypotheses is likely to provide the answer. The first hypothesis is that the Tuscola County Racerunners are a true relict population. This would be consistent with the idea that these lizards were historically linked with other midwestern racerunners and that they used a continuous habitat. The second hypothesis is that the Michigan Racerunners were either intentionally introduced or they accidentally escaped into the site before 1970.

Snakes Family Colubridae The broad classification Colubridae has traditionally been used to group the so-called advanced snakes under one umbrella. Presently a number of proposals to split this admittedly ungainly group into a number of smaller families are being debated, but the higher taxonomy of the snakes is far from settled, so in this book I will retain the traditional view. Thus, all the snakes in Michigan are in the Family Colubridae, with the exception of the state’s only venomous snake, the Eastern Massasauga (Sistrurus catenatus catenatus), which is in the Family Viperidae. The colubrid snakes (as defined here) make up about 80 percent of the snake species of the world. Colubrids are the dominant snakes on all continents except Australia. In eastern and central North America they make up about 85 percent of the snakes. The colubrids are generally active, nonburrowing species. Most of them have solid teeth, but some have grooved fangs in the back of their jaws. Some osteological (skeletal) characters that in combination generally define this group include the following (Holman1995b): 1. Hollow fangs are not present, and the maxilla (an upper jaw bone that bears hollow fangs in the Viperidae) is not retractable. 2. No remnants of limb girdle bones are present. 3. Teeth are present on the upper and lower jaw bones as well as several other bones of the skull. 4. The vertebrae (jointed units of the backbone) are usually longer than wide and lightly built. 5. The neural spines (ridges on the top of the vertebrae) are relatively long and thin. Colubrids occur worldwide except in very cold areas. A comprehensive book on the snakes of the United States and Canada is that of Ernst and Ernst (2003).

Clonophis kirtlandii (Kennicott 1856) Kirtland’s Snake Identification The little Kirtland’s Snake has four rows of rounded blotches that alternate with one another as they run down the back and sides of the body. The background color of these snakes is usually reddish brown but may be grayish brown in some individuals. The head is only slightly wider than the neck and is usually black. The scales on the lips, chin, and throat are white, cream, or yellow. The belly is usually reddish orange (sometimes pinkish orange), with a row of black spots on each side. The scales have keels (a single, thin, lengthwise ridge in the top center of each scale), and the anal plate (a large scale that partly covers the vent and may be single or divided) is divided. The total length of this snake ranges from about 360 to 622 mm (14.2–24.5 in.). General Distribution This species occurs from west-central Pennsylvania to extreme northeastern Missouri and throughout most of Ohio and Indiana to north-central Kentucky and Illinois (Minton 2001). Ernst and Ernst (2003) caution that the records of this snake in Missouri and Wisconsin are old and based on single individuals and that it is doubtful viable populations occur in these states. Michigan Distribution This snake is rare in Michigan and occurs only in the southwestern part of the state in Muskegon, Ottawa, Van Buren, Kalamazoo, Berrien, and Cass counties. It has also been recorded from the southeastern part of the state in Washtenaw and Lenawee counties. Geographic Variation No distinct populations of Kirtland’s Snake have been described in Michigan. Bavetz (1994) reported a small amount of variation in dorsal blotch number and head scutellation in Illinois. No subspecies of Kirtland’s Snake has been described. Habitat and Habits Kirtland’s Snake is a creature that favors moist habitats in natural situations near streams, ditches, marshes, and

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ponds, although the snake is not truly aquatic. Ruthven et al. (1928) reported that when it is near the water it will dive to the bottom like a true watersnake. I am not aware that this statement has been confirmed by any other sources though. Natural habitats in the Great Lakes region consist of “open grassy habitats such as wet prairies, wet meadows, fens, swales, and pastures,” Harding (1997, 267) reported; “they also occur in swampy woodlands, particularly in the unglaciated (southern edge) of its range.” In states where this species is more abundant, it is (or has been) strikingly abundant in some urban areas. With reference to Indiana and Louisville, Kentucky, Minton (2001, 279–80) stated that “Kirtland’s Snake is unique in being known best from populations inhabiting metropolitan areas. Fully half the Indiana specimens have been collected within the present city limits of Indianapolis.” Also, “in 1986 Department of Natural Resources personnel removed 44 Kirtland’s Snakes from a threatened inner city population in two days. However, the snakes are still common at this site.” He further reported that in the greater Louisville area, the urban populations are usually in grassy areas with a clay soil with some water source nearby. Here they are found under rubbish such as cardboard, metal sheets, and boards. The earthworms living under such objects are a staple in the diet of these snakes. P. W. Smith (1961) reported populations of this snake from Cook County, Illinois (Chicago and suburbs), and Conant (1951) reported populations from Toledo and Cincinnati, Ohio. Minton

(1972) found an individual in Indianapolis at virtually the same spot three times in one year, which indicates this species prefers selective shelters within their home ranges. My first experience with large numbers of snakes came when I was a sixth grader at Public School 85 on the east side of Indianapolis. Here, a poorly drained area covered with flat pieces of trash yielded many “redbellied spreaders” during a wet spell in April. Kirtland’s Snakes flatten their whole body when they are picked up or molested. The last time I saw Dr. Minton, he told me this colony had been extirpated. The only natural habitat where I ever found a Kirtland’s Snake in Indiana was in a grassy area near a small natural creek in Brown County in the south-central, unglaciated part of the state. In Toledo, Ohio, 43 percent of the Kirtland’s Snakes captured during a study were caught in April, and 18 percent were caught in May; males were more abundant in the spring, and females were more abundant in July and August (Conant 1943). Chimney crayfish burrows occur near populations of Kirtland’s Snake in both urban and natural areas, and it has been reported that these burrows are a preferred retreat (Harding 1997). Tucker (1994a) studied the burrowing behavior of Kirtland’s Snake captured from Effingham, Illinois. In twenty trials on native substrates, no inclination to burrow occurred in these snakes. On the other hand, if artificially made burrows were provided, in thirty-two of forty trials, the snakes were found hiding in the burrows. Once the snakes were inside the burrows they tried to squeeze

FIG. 79. Kirtland’s Snake (Clonophis kirtlandii) from Indiana. Photograph by James H. Harding.

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2. Species Accounts

into cracks and crevices in the sides of the burrows. This behavior was aided by their ability to extremely flatten their body. As a result of the burrowing trials, it has been suggested that management of the species should protect burrow-constructing animals such as crayfish. Parenthetically, I know of no other North American snake that can flatten its entire body to the extent that Clonophis kirtlandii does. Kirtland’s Snakes are active mainly at night, especially during the summer; the daylight hours are spent underground or sheltering under such objects as logs, piles of leaves, and in urban areas, deeply settled under large pieces of rubbish. Minton (1972) reported that in many Indiana localities Kirtland’s Snake is associated with Gartersnakes (Thamnophis sirtalis) and Brownsnakes (Storeria dekayi). The latter two snakes are not uncommon in urban areas in Michigan (Holman et al. 2006), and perhaps this association will someday turn up in Grand Rapids, Kalamazoo, Lansing, or Detroit too. Reproduction and Growth Minton (1972, 234) reported that “on May 1 at Indianapolis I found a pair of Kirtland’s Snakes in copulation under a piece of linoleum. The day was very warm, about 90ºF., but the spring had been cool. The snakes were very tightly intertwined and remained together after being placed in the collecting bag.” Litters of Kirtland’s Snake average eight young, based on forty litters examined in Ohio (Conant 1943). A gravid female collected in Illinois on May 16 had her young on September 23 and 24 (Powell and Parmerlee 1991). The young of this species are born alive. They are much darker than the adults, with indistinct dorsal blotches and bellies that are deeper red. The mean size of the newborns based on fifty-two individuals is 143 mm (5.63 in.), truly tiny little snakes. About their growth, Minton (1972, 235) stated “ten young snakes of an Indianapolis vacant lot population were marked by scale clipping. One measuring 175 mm. when collected on August 16 measured 215 mm. when recaptured June 6 of the following year. Another measured 195 mm. when captured April 12. It was 250 mm. when recaptured June 23 and had increased to 350 mm. on September 22. All three captures, incidentally, were virtually in the same spot.” Parenthetically, this very restricted site fidelity is probably why these populations are so concentrated.

Diet The staples in the diet of these little snakes consist of earthworms and slugs, which undoubtedly are one of the main reasons it is able to exist in the middle of urban areas. As a seventh grader, I kept two large Kirtland’s Snakes that I caught in a nearby vacant lot in east Indianapolis in mid-April into the summer. Both flattened when first caught but did not bite or secrete a musky fluid. They settled down immediately in the terrarium, crawling under a large slab of broken flower pot, and never flattened again. The second day after capture, they fed voraciously on worms and slugs and continued to do so until they were released in midAugust. Other food, such as minnows, crayfish, and a water strider have been reported as food for this species, and captives have been reported to eat leeches (e.g., Ernst and Ernst 2003). Tucker (1994b) studied the feeding behavior of four captive Kirtland’s Snakes from Illinois in a simulated “normal” environment that included burrowing earthworms. Three times the snakes were observed to crawl out of their hiding places and assume an alert Z-shaped position with the head raised. When an earthworm was placed in the vicinity of a snake, tongue flicking increased, and the snake searched for, found, and attacked the worm. Five times snakes that were initially seen in the “Z” position were later seen swallowing worms, but other times Z-position snakes went back to their hiding places with no further predatory activity. Kirtland’s Snakes were observed in earthworm burrows, either attacking and swallowing the worms (two instances) or in the act of swallowing the worms (two instances). The snakes were never seen pursuing an earthworm into a burrow. Predation and Defense Minton (2001) reported that an Eastern Black Kingsnake found near New Albany, Indiana, had eaten a Kirtland’s Snake and that another snake of this species that was partly eaten by an unknown predator was found in a marsh near Delphi, Indiana. Brown (1987) reported a case of American Bullfrog predation on this snake in central Illinois. Harding (1997) speculated that they are probably vulnerable to burrowing animals such as Eastern Milksnakes, shrews, and weasels; and that when above ground they would be vulnerable to hawks, owls, foxes,

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raccoons, skunks, and cats. Ernst and Ernst (2003, 77) stated that “when first discovered, Clonophis often flattens its body and becomes rigid. If further disturbed, it may thrash about or strike and spray musk.” C. H. Pope (1944, 190–91) stated that “if touched, or disturbed in some other way, a rigid individual [C. kirtlandii] suddenly throws a fit of violent, erratic wriggling that makes capture difficult. Some specimens strike but seldom do they really bite, and all can be handled with safety.” Interaction with Humans I heard a few wild rumors about “red-bellied spreaders” being venomous when I was a kid, but I think in most cases the relationship between Kirtland’s Snake and humans is a passive one. I have seen dead ones that were run over in the road both in Indiana and Illinois. Also, some of these snakes are coveted by reptile hobbyists (Harding 1997). Behavioral Characteristics For the behavioral characteristics of Kirtland’s Snake, see the sections “Habitat and Habits,” “Reproduction and Growth,” “Diet,” and “Predation and Defense” in this account. Population Health The Kirtland’s Snake is listed as Endangered in Michigan because few records for this species are recent. It is thus illegal to take or possess this snake without a scientific collector’s permit issued by the director of the MDNR. Any sightings of this snake, however, should be reported to the Wildlife Division of the MDNR. Harding (1997, 268–69) stated that “conserving this species will require identifying and protecting critical habitats, both in urban and rural areas. Legal protection by all states within its range would curtail pet trade exploitation, but a publiceducation campaign would be more effective in reducing incidental collecting and gratuitous killing.” General Remarks Because records of this species are rare, the professional people who look for these animals are loathe to discuss specific localities where these snakes are found, and I agree with this position. But I would like to know whether any truly urban populations of these snakes exist in Michigan.

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Coluber constrictor foxii (Baird and Girard 1853) Blue Racer Identification The Blue Racer is a large, very active snake that ranges from about 1.22 m (4.00 ft.) to 1.83 m (6.00 ft.) in total length. It has a shiny, solid-colored, bluish, greenish, or grayish back and a light blue belly. The head is somewhat darker than the body, and the lips, chin, and throat are white. Newly hatched and young Blue Racers look much different from the adults because they have a pattern of reddish-brown or gray blotches and spots on a gray background color. This pattern diminishes as the young snakes mature and is usually gone by the time they are about .91 m (2.99 ft.) long (Holman et al. 2006). General Distribution The Blue Racer occurs from southwestern Ontario, Michigan, Wisconsin, and southeastern Minnesota south to Ohio, Indiana, and Illinois (Ernst and Ernst 2003). Michigan Distribution The Blue Racer occurs in the Upper Peninsula but only in Menominee County. It does not occur on any Michigan islands. It is widespread only in about the southern third of the Lower Peninsula and extends northward in the western part of the state to Benzie and Grand Traverse counties. Somewhat isolated records occur in Clare County in the center of the Lower Peninsula and in Otsego County, three counties north of Clare. Geographic Variation I am not aware of any distinct populations of the Blue Racer in Michigan. All together eleven subspecies of Coluber constrictor are presently recognized in the United States and Mexico (Crother 2008), and all eleven of these occur in the United States. Of these subspecies, C. c. constrictor, the Northern Black Racer, occurs to the east; C. c. priapus, the Southern Black Racer, occurs to the south, and C. c. flaviventris, the Eastern Yellow-bellied Racer, occurs to the west of the Blue Racer (see Conant and Collins 1998, 339, map). Ernst and Ernst (2003) stated that some herpetologists believe the Blue Racer

2. Species Accounts

to be merely a color morph of the Northern Black Racer. Minton (2003) recognized a very broad zone of intergradation in central Indiana between the Blue Racer to the north and the Southern Black Racer to the south (see Minton 2001, 291, map). Habitat and Habits Blue Racers prefer relatively dry, sunny habitats that include hedge rows, old fields, shrubby fence lines, thickets, open woodlands, and woodland edges. In certain areas in southern Michigan, these snakes may be found hunting in brambly areas next to ponds and marshes, places where Northern Ribbonsnakes are also active. Ruthven et al. (1928, 86–87) reported that “the blue-racer is most frequently seen in dry, open situations, generally near or in thickets. It also frequents hedge rows and stone walls. It is a good climber and is not infrequently found several feet from the ground in bushes and twenty or thirty feet up in trees.” I can find no other references that report occurrences of Blue Racers high up in trees. Minton (2003) reported that in northwestern Indiana, Blue Racers inhabit old dunes, sparse woods, and sand prairies. He mentioned that Racers in Indiana avoid dense woods and heavily cultivated areas. Ernst and Ernst (2003) stated that throughout most of their range, Racers come out of hibernation from late March to May (I have not seen Blue Racers before May in Michigan) and that they go into hibernation from September to November. Harding (1997) reported that Racers in the Great Lakes region hibernate in mammal

Fig. 80. Blue Racer (Coluber constrictor foxii) from Jackson County, Michigan. Photograph by James H. Harding.

burrows, crayfish burrows, rock crevices, rotting stumps, old building foundations, and other places that provide them refuge from freezing temperatures. On October 7, 1975, in the midafternoon, I stumbled across Blue Racers entering and leaving what appeared to be a partly filled-in woodchuck burrow at the base of a very large American beech (“blue beech”) tree. The site was next to a bicycle path through a wooded area near Okemos (a village near East Lansing, Michigan). I observed two of these snakes entering and three emerging from the hole within about fifteen to twenty minutes. I also saw other Blue Racers sunning both in low bushes and on the ground (one on the bicycle path) within twenty or so feet of the beech tree hole, which I believe must have been a hibernaculum. I also saw two Northern Ribbonsnakes in low bushes in the area, but saw no Ribbonsnakes entering or leaving the hole. It had been cold the night before and warm that afternoon—I would guess the temperature was above 70ºF. I visited the site again the following spring in early May. Oddly, no shed skins were in the vicinity nor was there evidence creatures had been coming or going from the hole. Rosen (1991a) reported that hibernating Blue Racers in Michigan had cloacal temperatures of 3.3 to 3.7ºC (37.9–38.7ºF), with an average cloacal temperature of 3.5ºC (38.3ºF). Blue Racers are often seen rapidly crawling about with their heads alertly raised off the ground. They also appear to streak across roads at high speeds. Actually, the top speed recorded by Mosauer (1932) was 5.6 kilometers per hour (3.47 miles per hour). Relative to this, Minton (2001) stated that he personally thinks Racers can do better than this for short distances. In Michigan, Rosen (1991a) took body temperatures of Blue Racers under various situations. Blue Racers on the move had body temperatures that ranged between 27.2 and 36.8ºC (81.0–98.2ºF). When the snakes were under cover on cool days, they had mean body temperatures of 22.2ºC (72.0ºF). Basking Blue Racers in Michigan had mean temperatures of 29.2ºC (84.6ºF). Racers in general have rather large home ranges, but the extent of this home range depends on the habitat and sex of the animals. In Michigan, large adult Blue Racers have an average of 424 m (1,391 ft.) between recaptures, yearlings 188 m (617 ft.), and small juveniles 66 m (216 ft.) (Rosen 1991a). Sometimes Racers must travel

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a relatively long distance from their area of activity to their hibernaculum and back. In Michigan, Blue Racers may disperse up to 2.2 km (1.36 miles) from their hibernacula (Rosen 1991a). Reproduction and Growth Courtship and mating in Racers, in general, occurs from April through July. In the Great Lakes region, mating is said to take place in early June (Harding 1997). During this season, males give the appearance of being very nervous and may be territorial. McCauley (1945) stated that males engage in combat behavior in the spring; however, this has not been reported by other herpetologists. In Michigan, male Blue Racers mature in eleven months to two years, but they do not mate until the second spring; females mature in two to three years (Rosen 1991). Female reproduction is annual with a single clutch of eggs produced each year. C. H. Ernst, in a personal observation reported in Snakes of the United States and Canada (2003), stated that when a female is found, the male Racer crawls alongside and examines her with his tongue. He then crawls onto her back and waves his body from tail to head. He then puts his vent next to hers. The female lifts her tail when she is receptive, and the male inserts one of his hemipenes as the snakes entwine. The two snakes either lie still in copulation, or the female may crawl about, dragging the male along with her. After the male ejaculates, he withdraws from the female and crawls away. I observed the mating activity of Coluber constrictor in south-central Indiana in 1953, a description of which I sent to Sherman A. Minton in a letter. This was quoted by Minton (2001, 292) as follows: “J. A. Holman wrote me of a pair seen May 5 in Brown County. The male was observed first chasing the female, and the two snakes wound in and out of low bushes with amazing rapidity. At last the female stopped and copulation took place. The male . . . was belligerent and struck at me, while the female glided quickly away.” Harding (1997) reported that female Racers lay from three to thirty-two eggs in June or early July in a nest hidden from view in mammal burrows, rotting stumps or logs, a cavity in sand, sawdust piles, or leaf litter. Sometimes female Racers share nesting sites. The eggs are oval and range in length from 25 to 39 mm (.98–1.54 in.). When the eggs are first laid, they

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have flexible shells with a granular covering. During the incubation period, the eggs nearly double in size and become much less flexible. The hatchlings usually emerge in August. Rosen (1991a) reported that Michigan Blue Racers grow approximately 279 mm (10.98 in.) the first year, 237 mm (9.33 in.) between years one and two, and 106 mm (4.17 in.) in their third year. Diet Blue Racers will often chase down their prey rather than slowly stalking it to the point of capture or lying in wait for it, as do many other kinds of snakes. Blue Racers are not constrictors and were labeled with their specific name because of a misinterpretation by a very early writer. When Racers catch relatively small animals, they are quickly swallowed. If the prey is larger, such as a large mouse or shrew, it may be held down by the body of the snake while the prey is chewed to death before being swallowed. In 1975 I kept a large male and female Blue Racer from southern Michigan for two months in a large mammal cage that allowed them plenty of room to move around. I also arranged a simulated small brush pile for them to hide in. At first, when they were out of the brush pile, they would coil and vibrate their tails at my approach, but within a very few days they settled down. When they rested in a corner of the cage or sheltered in the brush pile, they always maintained body contact with each other. They ate laboratory mice and held them down with a fold of their body while vigorously chewing the head and neck. A mouse died within seconds from the bites of these large snakes. When I had to handle the snakes for one reason or another, they usually struck at me immediately with no provocation, and both landed a bite or two. A visiting herpetologist attempted to gently pick up the female with a gloved hand and was struck on his nose, which bled profusely for many seconds. When I released the snakes into the area from which they had come, they both glided away in tandem and at high speed, disappearing into a brushy area. I once watched a large Racer pursuing a Leopard Frog in south-central Indiana in 1953. The frog attempted to dodge the snake by a series of random, alternating leaps and stops that confused me but not the snake, which emerged into an open area with the frog in its mouth and then quickly crawled into a bramble patch.

2. Species Accounts

Racers in general are opportunistic feeders, unlike many other large snakes that tend to have somewhat more restricted diets. Some broad categories of animals that Racers eat include shrews, bats, moles, squirrels, lemmings, voles, mice, jumping mice, rats, small weasels, birds, small turtles and turtle eggs, lizards, snakes (including rattlesnakes), frogs, toads, salamanders, insects of many kinds, and some kinds of spiders (see Ernst and Ernst 2003 for a detailed list of species). Klimstra (1959) conducted a detailed study in Illinois of Racer prey and found the following percentages of occurrence in stomach contents: insects, 48 percent; mammals, 43.5 percent; birds, 16.5 percent; amphibians, 13 percent; and reptiles, 12 percent. Minton (2001) examined the contents of the stomachs of forty-two Racers in Indiana. He reported that as many as three types of food were found in single stomachs. Fourteen snakes had eaten insects and those were the only food items in ten of the stomachs. The insects eaten consisted of grasshoppers, crickets, cicadas, caterpillars, and beetle larvae. These insects were found in the stomachs of both large and small snakes. Mammals occurred in twelve stomachs. Meadow voles were found in seven stomachs, and unidentified mice and a small chipmunk were found in the other five stomachs. Birds or bird eggs occurred in five stomachs. Snakes were found in eight stomachs, and one snake was caught while eating a small Watersnake. Most of the other consumed snakes were Gartersnakes or Rough Greensnakes. Two young Racers had eaten treefrogs, and several Leopard Frogs were found in one adult. Five Racers had eaten lizards, and two had eaten hatchling Box Turtles. Predation and Defense Racers have many predators. Some broad categories of these predators include shrews, opossums, mice, badgers, skunks, domestic cats, bobcats, eagles, hawks, kestrels, shrikes, crows, snakes (including Racers themselves), glass lizards, and ground beetles (see Ernst and Ernst 2003 for a more detailed list). Harding (1997) reported that in the Great Lakes region, Racers are preyed upon by larger Racers and other snake-eating snakes, hawks, crows, and mammals such as raccoons, skunks, foxes, and domestic dogs and cats. I have seen dogs kill snakes, but I have never seen one eat a snake.

I once encountered a Racer in a struggle for its life in the coils of a Common Kingsnake (Lampropeltis getula) of about the same length (but of somewhat greater bulk) in Alachua County, Florida, in a pine flatwoods on May 2, 1958. At one time the Racer, whose head was free and was chewing on the Kingsnake’s body, actually seized the head of the Kingsnake and tried to swallow it. But the Kingsnake, tightening its coils, was able to wrench its head from the Racer’s mouth and finally disable it during the next few minutes. It took the Kingsnake about half an hour to completely ingest the Racer. The best defensive behavior the Blue Racer has is its ground speed and rapid climbing ability in low vegetation. Most of these snakes will immediately flee a predator or approaching person if given the chance to do so. Most of the Blue Racers I have surprised in the wild seem to know where the nearest safe havens are, as they immediately head for bushes, brambles, thickets, or other close vegetation. Oddly, I have not seen them run to holes, but I would not be surprised if burrows or holes are available within these shelters. If cornered or cold, these snakes are not intimidated and will coil and strike while vibrating their tail. Blue Racer bites produce very small punctures in humans, but they do bleed profusely for quite a few seconds. I have never heard or read of a human having either a toxic or allergic reaction to the saliva introduced by the Racer during these bites. Interaction with Humans Unfortunately, Blue Racers have been needlessly persecuted for years in all parts of their range in the United States. The frustration suffered by Michigan naturalists because of this slaughter was summed up years ago by Ruthven et al. (1928, 87–88), who stated that “the senseless slaughter of this beautiful snake is as much a disgrace to any civilized community as is the similar destruction of song birds, and an all too common occurrence in southern Michigan. Large and conspicuous, the adults often fall prey to the ignorance and superstition of people who should know better. The writer recalls an instance where a farmer showed him with great satisfaction six splendid specimens, not one of them under five feet, which he had killed in a brush pile, under the impression that he was greatly benefitting the community by ridding it of six very dangerous

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animals.” During my time in Michigan, I have seen Blue Racers clubbed to death by people along trails in nature preserves and deliberately run over by cars, although many fewer now than during the past twenty years, I am happy to say. Relative to the conservation of this snake in Michigan, people must realize that Blue Racers require large areas of habitat because they have large home ranges. Populations are quickly diminished in areas where agriculture is intensive or urban sprawl encroaches into rural areas. Indirectly, the destruction of wetlands is harmful to Blue Racers because they feed on frogs and other amphibians that need these sites to reproduce and on voles that live in the marginal areas of swamps and marshes. Blue Racers are of economic value to humans because they destroy rodent and insect pests.

Diadophis punctatus edwardsii (Merrem 1820) Northern Ring-necked Snake

Behavioral Characteristics For the behavioral characteristics of Blue Racers, see the sections “Habitat and Habits,” “Reproduction and Growth,” “Diet,” and “Predation and Defense” in this account.

General Distribution Northern Ring-necked Snakes occur from Nova Scotia, Canada, west to northeastern Minnesota and south through New England and the Appalachian highlands to northern Georgia and westward to southern Illinois (Harding 1997).

Identification The Northern Ring-necked Snake is a small velvety snake with a slate gray to bluish black back and sides, and a bright yellow or orange ring around its neck. The scales of the body are very smooth. The belly of this snake is a light yellow or yellowish orange color, either unmarked or with black dots scattered along the midline. In some individuals the head may be darker than the rest of the body. The anal plate is divided. The hatchlings resemble the adults in these characters. The total length of an adult ranges from 254 to 706 mm (10.0–27.8 in.).

Population Health The Blue Racer is not protected in Michigan, although there is no question that its populations have become greatly diminished in recent years. This species was not uncommon at the edges of woodlots, railroad rightsof-way, and marshes near the Michigan State University farms, and even on the campus proper when I arrived here in 1967, but I have not seen a Blue Racer in these areas in the last twenty years. Some of this has resulted, I am sure, from well meaning but misguided removal of brush, boards, and other “trash” from the edges of woodlots, and especially from the edges of railroad tracks and ponds on the university property. I am sure similar detrimental “cleanup” has happened in other public areas in the state. General Remarks Blue Racers may be moving northward in Michigan in the western part of the Lower Peninsula near Lake Michigan (Douglass 1977; Holman 1992). A reason for this expansion may be the creation of sunny areas and new habitats by deforestation. FIG. 81. Northern Ring-necked Snake (Diadophis punctatus edwardsii) from Roscommon County, Michigan. Photograph by James H. Harding.

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2. Species Accounts

Michigan Distribution The Northern Ring-necked Snake occurs in every county in the Upper Peninsula of the state as well as on Bois Blanc Island and Beaver, Garden, North and South Fox, and North and South Manitou Islands in the Lake Michigan Archipelago. It is widespread in the northern third of the Lower Peninsula. South of that area, it is moderately common in coastal western Michigan, but it has not been recorded from most of the rest of lower Michigan except for Oakland, Washtenaw, Eaton, and Jackson counties. This species is absent from so many counties in the southern two-thirds of the Lower Peninsula that it does not seem wise to attribute the reason to a lack of collecting in the region. During my tenure in Michigan, I have never seen a Ring-necked Snake in the southern half of the Lower Peninsula. Geographic Variation I am not aware of any distinct populations of Northern Ring-necked Snake in Michigan. Eleven subspecies exist elsewhere, though, within this species (Crother 2008), and some of them are very different (see Ernst and Ernst 2003, 91, illustrations; note that the upper and middle captions are reversed). In the southeast the Northern Ring-necked Snake is replaced by the Southern Ring-necked Snake (D. p. punctatus). To the southwest is the Mississippi Ring-necked Snake (D. p. stictogenys). In southwestern Illinois, the Northern Ring-necked Snake intergrades with the Prairie Ring-necked Snake (D. p. arnyi) (Conant and Collins 1998, 331, map). Habitat and Habits In Michigan, the Northern Ring-necked Snake prefers moist, shaded woodlands or their edges. It is a secretive snake that shelters under flat objects of various kinds or the bark of dead trees. It is rarely seen on the surface. Some of the other subspecies of Diadophis punctatus have very different habitats than the Northern Ring-necked Snake, especially those in the western United States. Harding (1997) suggested that the active period of this snake probably extends from early April to late October in the southern part of the Great Lakes region and from late April or early May to mid- or late September in the northern part of the region. Most of the daily activity of Diadophis punctatus is nocturnal, but sometimes, especially during the breeding season,

daylight activity may occur (Ernst and Ernst 2003). Ring-necked Snakes also have some climbing ability, and they have been found 1 to 2 m (3.28–6.56 ft.) above the ground, hidden beneath the bark of dead trees. Blanchard et al. (1979) found that in northern Michigan, Northern Ring-necked Snakes made spring and fall migrations to and from their hibernating sites, which consisted of burrows, cisterns and wells, stone walls, brush piles, rotten logs and stumps, sawdust piles, rock outcrops, and buildings. They found it was not unusual for several snakes to share the same hibernaculum. Minton (2001) reported that in Indiana these snakes are the most plentiful of the small snakes in the moist ravines of west-central and southeastern Indiana, but that they are uncommon in the dry knob habitats near New Albany. He also commented that they are uncommon in forest bottomland and absent in Indiana’s prairie regions. Reproduction and Growth Observations of courtship and copulation are rare for Ring-necked Snakes, and I am not aware of any reports on this subject from Michigan or the Great Lakes region. It is known that pheromones (chemicals released from the skin that influence the behavior of other animals) of female Ring-necked Snakes attract males and cause them to aggregate in the spring and fall for mating (Dundee and Miller 1968). Fitch (1975) and Nussbaum et al. (1983) have provided some data on courtship and mating in Kansas and the Pacific Northwest, respectively. During courtship the male rubs his closed mouth along the side of the female as he moves beside her. When he reaches her neck ring, he bites her at that location. Then he moves the lower part of his body next to hers, wraps his tail around hers, and inserts one of his hemipenes. In reference to the Great Lakes region, Harding (1997, 327) stated that “nests may be in rodent burrows, beneath flat rocks or boards, or within rotted logs or stumps; several females will often share a particular favored spot, which may be used for several consecutive seasons.” Blanchard (1942) discovered forty-eight and fifty-eight eggs in two communal nests. The elongate eggs are about 25.4 mm (1 in.) long and have rough, thin, leathery shells. During the incubation period, the eggs absorb water and become larger. Hatchlings range from about 90 to 140 mm (3.5–5.5 in.) in length (Harding 1997).

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Blanchard et al. (1979) reported on the growth rate of Northern Ring-necked Snakes in northern Michigan using estimated lengths. They found that females in their first year increased in length by 60 percent, in the second year by 23 percent, in the third year by 18 percent, in the fourth year by 17 percent, and in the fifth year by 17 percent. The males increased in length in their first year by 68 percent, in the second year by 24 percent, in the third year by 8 percent, and in the fourth year by 11 percent. Fitch (1975) found an essentially similar growth rate in Kansas.

1974); one individual was bitten several times without any symptoms at all (Henderson 1970). With regard to Northern Ring-necked Snakes, Harding (1997, 326–27) explained that “this species has a pair of slightly enlarged teeth at the back of the upper jaw, and its saliva may be mildly toxic to small animals. By any measure, however, Northern Ring-necked Snakes are completely harmless to humans.” I must add that humans may react differently to the same toxin and that special care should be taken in handling Ring-necked Snakes, especially the large western subspecies, which can easily grab a finger, if so inclined.

Diet Northern Ring-necked Snakes in Michigan feed on such items as earthworms, small amphibians (especially Eastern Red-backed Salamanders), and sometimes small snakes. Harding (1997) reported that in the northern part of the Great Lakes region Red-backed Salamanders appear to make up a large part of this snake’s diet, followed in frequency by small snakes and earthworms. Different subspecies of Diadophis punctatus have somewhat different food habits, depending on where they occur in the United States. Western forms, for example, eat western snake and lizard species that do not occur in the eastern United States, and this may lead to different feeding behaviors in these subspecies (Gehlbach 1974). In Virginia, the diet of Diadophis punctatus is 80 percent salamanders (Uhler et al. 1939), amphibians that are not available in many parts of the arid west. Minton (2001) found a Northern Ring-necked Snake eating a Ravine Salamander in Switzerland, Indiana. He also recorded three other Indiana Ring-necked Snakes that had eaten plethodontid salamanders and a fourth that had eaten earthworms. Ring-necked Snakes appear to locate their prey by scent (Lancaster and Wise 1996). Diadophis punctatus is mildly venomous, having enlarged posterior teeth that allow toxic saliva to flow into their prey. Lizards and salamanders are held in the mouths of these snakes and chewed upon until they stop struggling. Ring-necked Snakes seize earthworms at any point along their body and then chew toward one end or the other before beginning to swallow (Ernst and Ernst 2003). The few instances of human bites by Diadophis punctatus have produced a “burning sensation” in some people and no symptoms in others (Myers 1965; Shaw and Campbell

Predation and Defense Harding (1997, 327) stated that “during their occasional surface forays, they [Northern Ring-necked Snakes] risk being eaten by owls, hawks, foxes, domestic cats, and other surface hunters. Predators willing to enter burrows or dig, such as Eastern Milk Snakes, Racers, shrews, weasels, and skunks, are a more constant threat.” Rossi and Rossi (1994) gave a fascinating account of how the toxic saliva of a Southern Ring-necked Snake saved its life. The snake was attacked by a captive Longnosed Snake (Rhinocheilus lecontei) and remained motionless and was almost swallowed when it turned its head ninety degrees and grabbed the floor of the mouth of the Long-nosed Snake, holding on for sixteen hours until the predator died. The Southern Ring-necked Snake eventually emerged from the other snake and crawled away. Ring-necked Snakes have several other defensive behaviors: squirming, releasing strong musk, tucking their heads under body coils while displaying their bright undersides, and even feigning death. I have collected many Northern Ring-necked Snakes in Indiana and have observed only the squirming and musk-releasing behavior. None of these animals tried to bite. Minton (2001, 329), though, has witnessed other defensive behaviors in Indiana: “Curling and elevating the tail, a common defensive reaction in some other forms of Diadophis, is rarely seen; however, a Perry County snake found on a cool 59º day reacted with both tail curling and death feigning.” The Northern Ring-necked Snakes I have found in Michigan have been very nervous and squirmy compared to those I have handled in Indiana and elsewhere. I have also been surprised by how active they are at relatively low temperatures.

2. Species Accounts

Interaction with Humans Since Northern Ring-necked Snakes are not commonly observed in Michigan, I can state only that the interaction with humans is passive. When I have talked to people in other states about this species, they have almost unanimously stated that they consider it to be a pretty (or some other such word) and harmless little snake. Behavioral Characteristics For the behavioral characteristics of Northern Ringnecked Snakes, see the sections “Habitat and Habits,” “Reproduction and Growth,” and “Predation and Defense” in this account. Population Health Blanchard et al. (1979) studied Ring-necked Snakes in northern Michigan and estimated that the population size in their study area was 77 to 150 snakes. Because many of the snakes that were marked were never caught again, they concluded a large number of the snakes were transient. The juvenile-to-adult ratio at this site was one juvenile for every eight adults, which these authors thought was an indication of how secretive the young are rather than of a high rate of mortality in these tiny animals. The Northern Ring-necked Snake is not protected in Michigan, but this snake tends to occur in colonies that could be rapidly extirpated if an area where they live is disturbed or taken over by urban expansion. Since this species prefers moist woodlands, both clear-cutting and selective logging could be detrimental to its survival in the state. General Remarks More surveys are needed to determine whether Northern Ring-necked Snakes exist in the many counties of the Lower Peninsula where they have not been recorded.

Heterodon platirhinos Latreille 1801 Eastern Hog-nosed Snake Identification The Eastern Hog-nosed Snake is a thick-bodied snake with a relatively large head that has an upturned, flattened snout. The flattened snout is really the key character for the identification of this snake in Michigan, as no other snake in the state has such a structure. The neck-flattening, hissing, bluffing, and death-feigning behaviors of this snake are also a help in identifying this harmless creature. The coloration is highly variable in this species. Often they have a distinct pattern of irregular dark blotches that run down the back and alternate with dark spots on the sides. The background color ranges from gray or brown to yellow or pink. Some individuals are entirely black, and others lack blotches and are just plain gray, brown, or olive. The scales of Heterodon platirhinos are strongly keeled, and the anal plate is divided. Male Eastern Hog-nosed Snakes are less robust than females and have longer tails. Hatchling and juvenile Eastern Hog-nosed Snakes look enough like the adults to be easily identified. The total length of adults ranges from 500 to 1,156 mm (19.7–45.5 in.). General Distribution The Eastern Hog-nosed Snake has a wide range, from southern New England southward through Florida, then west to central Texas and north to southeastern South Dakota, southern Iowa, and eastern Minnesota, and east to Ontario, Canada. Presently three other species of Heterodon are recognized (Crother 2008). These are Heterodon nasicus Baird and Girard 1852, the Western Hog-nosed Snake; Heterodon gloydi Edgren 1952, the Dusty Hog-nosed Snake (a newly recognized species from eastern Texas that was previously a subspecies of H. nasicus); and Heterodon simus (Linnaeus 1766), the Southern Hog-nosed Snake. Michigan Distribution The Eastern Hog-nosed Snake is absent from all of the Upper Peninsula except Menominee County, which is adjacent to Wisconsin. This species has not been recorded from any Michigan islands, as far as I am aware.

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Heterodon platyrhinos is widely distributed in the Lower Peninsula, although it has been recorded only from Huron County in the thumb area and is oddly missing in a block of counties including Montcalm, Gratiot, Saginaw, and Shiawasee.

FIG. 82. Eastern Hog-nosed Snake (Heterodon platirhinos) from Kalkaska County, Michigan. Photograph by James H. Harding.

Geographic Variation Although numerous color variations are seen in Eastern Hog-nosed Snakes in Michigan, none of them has been documented in any single definable population or area in the state. No subspecies are presently recognized in Heterodon platirhinos (Crother 2008). Habitat and Habits Habitats with well-drained, sandy soils are preferred by Eastern Hog-nosed Snakes. In Michigan they can be found in deciduous woodlands, mixed conifer and broadleaf forests, and open pine forests. They also turn up in fields, pastures, and meadows; near lakes; and in the yards of lakeside homes. They are fairly characteristic of dune habitats in the state. Eastern Hog-nosed Snakes are more highly adapted for burrowing than any other snakes in Michigan. Their broad, flat heads and turned-up snouts push both downward and from side to side when they make their excavations. When these snakes are not looking for a mate or foraging, they will burrow into sand or loose soil, thus protecting themselves from chilling, overheating, and predators.

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It is not impossible that this behavior could save them from fires as well. Ernst and Ernst (2003) found that this species is active mainly during the daytime, especially early in the morning. A shorter activity period occurs in late afternoon or at dusk. This activity may be more intensive during the frog and toad breeding season. A study in Antrim County showed that this snake moves an average of 60.5 meters a day and that home-range size varied from 2.5 to 76.1 ha (6.2–188 acres) (McDonald 2003). In the Great Lakes region, the Hog-nosed Snake hibernates from about late October to April in deep burrows of their own making or under rotted stumps or logs. Reproduction and Growth Male and female Eastern Hog-nosed Snakes in general are ready to breed when they reach a total body length of 510 mm (20.1 in.) (Conant and Collins 1998). This length is very near the size of maturity reported for both Kansas and Kentucky (Platt 1969; Ernst and Ernst 2003). The main breeding season of this species in Michigan is probably from about late April to middle or late May. In Wisconsin, a second breeding season may occur in September and October (Vogt 1981); this may also occur in Michigan. Since male Eastern Hognosed Snakes hibernate alone, they often must engage in a rather long-distance pursuit of females. Males may follow the pheromone trails of females in these situations (Plummer and Mills 1996). Nichols (1982) described the courtship and copulatory behavior of captive Eastern Hog-nosed Snakes. When a female is located, the male moves in beside her and contacts her side with his rostrum and tongue. He then crawls slowly toward her head. When he reaches the area of her neck he wraps his tail over hers, thrusts a loop of it under her tail, and attempts to insert one of his hemipenes into her vent by means of undulations. Soon these pulsations become waves of his body (caudocephalic waves) that move from the rear toward the head. During this period the female will either move slowly forward or become still. Sometimes the female will crawl away, dragging the anchored male along with her (Ernst and Ernst 2003). Copulation may take several hours. Relative to nesting in the Great Lakes region, Harding (1997) stated that in June or July, females will

2. Species Accounts

place a clutch of four to sixty-one eggs in a shallow burrow in sand or soil, or under a log or rock. The eggs have thin shells and are broadly oval or sometimes nearly spherical. They range in length from 21 to 39 mm (.83–1.54 in.). These eggs expand considerably in size during incubation. Hatching usually occurs in late August or September after an incubation of about sixtyfive days. Hatchling Eastern Hog-nosed Snakes are more strikingly marked and colored than the adults and have total body lengths of 127 to 294 mm (5.0–11.6 in.) (Ernst and Ernst 2003). The growth rate of hatchlings and juveniles is relatively fast, but it slows after sexual maturity. Females grow faster and become larger than male Eastern Hog-nosed Snakes. Platt (1969) found that his largest female grew from 685 mm (27.0 in.) to 748 mm (29.4 in.) in snout-to-vent length in less than a year at a growth rate of 10 mm (.39 in.) per active month. Diet Uhler et al. (1939) reported that, by volume, the major items eaten by Heterodon platirhinos in Virginia were toads, 40 percent; frogs, 30 percent; salamanders, 11 percent; and small mammals, 19 percent. In Kansas, Platt (1969) found that amphibians were present in 58 percent of the stomachs examined, and insects were in 35 percent. Holman et al. (2006) stated that the Eastern Hognosed Snake uses its upturned snout to dig for toads, which are its favorite food. Relative to the Great Lakes region, Harding (1997) stated that food recorded for the Eastern Hog-nosed Snake includes toads, frogs, salamanders, small reptiles, reptile eggs, small mammals, birds, and insects, but that toads are by far the most frequent food taken. Adaptations that Hog-nosed Snakes have for finding and eating toads include: 1. Digging abilities 2. A wide gape and recurved teeth (toads will inflate themselves with air to resist being swallowed) 3. Enlarged teeth at the back of the mouth (which not only maintain a firm grip on a toad but may be able to puncture and deflate it) 4. Enlarged adrenal glands (which secrete hormones that possibly aid in counteracting the toxic skin secretions of toads)

Predation and Defense Ernst and Ernst (2003) listed the predators of Eastern Hog-nosed Snakes, and those that could pertain to Michigan are Blue Racers, Ratsnakes, crows, red-tailed hawks, and barred owls. The defensive behavior of the Eastern Hog-nosed Snake is well documented and truly amazing. When confronted, this snake inflates its body with air. This behavior causes its pattern to stand out boldly. Its head and neck then spread out in a “cobralike” fashion, and it expels the air in its body, causing a very loud and long hiss. For this reason it is often known as “puff adder” or “spreading adder.” Its mouth then gapes widely, and the snake may or may not make fake strikes at the would-be predator or other tormentor. If these behaviors do not work, the snake puts on probably the most exaggerated death-feigning act in the animal kingdom. All of a sudden its movements become uncoordinated as it writhes and rubs its open mouth on the ground and often expels the contents of its stomach and cloaca. Also, it sometimes bleeds from the mouth. The last and final act occurs when the snake rolls over on its back, belly up, often with its tongue lolling out. If one backs off from the dead-looking snake and stays still for a few minutes, the snake’s head turns up and the air is tested slowly with its tongue. If the information the snake receives from this registers favorably, the reptile will right itself and crawl away as fast as its chubby body allows. If the snake is caught again and placed upright, it will go belly up again, giving away the stereotyped nature of the performance. Several reports have described how hatchling Hog-nosed Snakes, even those only partially out of the shell, will flatten, hiss, and indulge in other activities associated with bluffing and death-feigning. Of considerable interest is that Platt (1969) found no instances of predation on this snake during his extensive field studies in Kansas. He also made comments about there being few published records of predation on this species. In Michigan, I have picked up several Eastern Hog-nosed Snakes off the road and out of people’s backyards to save the snakes from imminent death. I found that some of these snakes, if handled very gently during their capture, would do nothing more than hiss and spread while being carried to a safer place. Parenthetically, I have found that many of the larger species of snakes will allow themselves to be moved if picked up slowly and confidently and handled gently.

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Interaction with Humans I could never convince my father that Eastern Hog-nosed Snakes were not “spreading vipers” whose very breaths were poisonous. He carried a long-handled axe in the trunk of his car, which he used to dispatch several of these snakes on dusty roads in Indiana as well as one in Michigan when our family first visited the state in 1940. He did this because of what his father had taught him. I am afraid this is still the attitude of some people, not only in Indiana and Michigan, but throughout the extensive range of this snake species. I still see evidence of Eastern Hog-nosed Snakes that were either beaten to death by various objects or purposely run over by cars in Michigan, and I have come to the conclusion that the best way to save this species in the state is through education. Hog-nosed Snakes have enlarged teeth in the back of their upper jaw that help them hold onto struggling prey. McAlister (1963) reported that the saliva of the Eastern Hog-nosed Snake is mildly toxic to amphibians but not mice. Hog-nosed Snakes rarely bite humans, but there are several reports of mild envenomation of humans by Hog-nosed Snakes, most of these involving the western species, Heterodon nasicus (Grogan 1973; Morris 1985; Minton 1990, 2001). Minton (2001) reported further that the only bite he received occurred when he picked up a large Eastern Hog-nosed Snake immediately after he had been handling toads. The snake literally swallowed his thumb before it was forced to let go. Minton was not envenomated but developed sporotrichosis, an irritating fungal infection, at the site of the tooth punctures. Harding (1997, 331) reported that “one person accidently bitten on the arm while handling an Eastern Hog-nosed Snake suffered subsequent pain and discoloration near the wound, leading to speculation that this snake’s saliva could be toxic to humans. However, this writer [Harding] was firmly bitten and chewed on the thumb while handling a large female Hog-nosed Snake (which was undoubtedly responding to the smell of a previously handled toad) and suffered only minor pinprick wounds.” I was bitten on the thumb in 1974 when offering an Eastern Hog-nosed Snake a thawed American Toad that had been killed on the road. The enlarged rear teeth punctured my thumb in two places, and the wounds bled profusely for a minute or two. Other than the bleeding, I had no symptoms at all, and

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the wounds quickly healed. Obviously people respond differently to mild envenomation, so Hog-nosed Snakes (especially the western species H. nasicus) should be handled with care, or perhaps even better, not handled at all. Behavioral Characteristics For the behavioral characteristics of Eastern Hognosed Snakes, see the sections “Habitat and Habits,” “Reproduction and Growth,” “Diet,” “Predation and Defense,” and “Interaction with Humans” in this account. Population Health Above and beyond the human penchant for directly killing Eastern Hog-nosed Snakes with sticks and cars is the effect of agriculture on their population health. The plowing each year of sandy fields not only kills individual snakes but also destroys their nest sites. The declining toad populations in many places throughout Michigan probably directly affects Eastern Hog-nosed Snake populations. General Remarks Eastern Hog-nosed Snakes are not protected by Michigan law at the present time, and some people are still keeping them as pets. Making a pet of them is really not a good idea, for toads and frogs are very hard to obtain for the winter feeding of these reptiles.

Lampropeltis triangulum triangulum (Lacépède 1788) Eastern Milksnake Identification This graceful species of the Kingsnake group (Lampropeltinae) is a slender, medium-sized snake with a row of brown or reddish-brown blotches on a background color of tan or gray. On its sides, the Eastern Milksnake’s blotches are saddle-like, edged in black, and arranged in alternate rows of smaller dark blotches. The head is relatively small, just slightly wider than the neck, and almost always bears a V- or Y-shaped light-colored marking at the back. The light-colored belly has an irregular checkerboard pattern of rectangular black spots. The scales of this snake are

2. Species Accounts

smooth, and the anal plate is single. The size of adults of this subspecies was given by Harding (1997) as ranging from 610 to 1,320 mm (24–52 in.). Frankly, I would be amazed to see a fifty-two-inch specimen in Michigan; most of the adult Eastern Milksnakes I have seen are about a yard long.

over naturally occurring areas (Kindsvatter 2004). Because of its secretive habits, less is known about its general behavior than that of many other snakes that occur in Michigan.

General Distribution The Eastern Milksnake occurs from Maine to Minnesota and south in the uplands to northern Alabama. This subspecies presumably intergrades with the Scarlet Kingsnake (Lampropeltis triangulum elapsoides) to the south of its range, and with the Red Milksnake (Lampropeltis t. syspila) to the west, in the central United States (Conant and Collins 1998). Other subspecies extend the range of this species west to Utah and Arizona and south into Mexico and Central America. Michigan Distribution This snake has been recorded from only two counties in the Upper Peninsula: Mackinac County in the eastern part of the UP, and Marquette County in the western part. The Eastern Milksnake has been recorded from Bois Blanc Island as well as Beaver, Garden, High, North Fox, and Whiskey Islands in the Lake Michigan Archipelago. Throughout the Lower Peninsula, it is widespread and relatively common except in a block of adjacent counties including Mecosta, Montcalm, Gratiot, Saginaw, Genesee, Lapeer, St. Clair, and Macomb. Geographic Variation I know of no populations of Eastern Milksnakes in Michigan that exhibit any consistent variations. Habitat and Habits The Eastern Milksnake is ubiquitous in its habitat preferences in Michigan. They inhabit natural habitats such as open woodlands and woodland edges, swamps and marshes, and lakeshores and stream edges. Modified habitats utilized by Eastern Milksnakes in the state include pastures, farmyards, and suburban homes with extensive backyards. They are often found in or near farms and sheds, and young ones often get into basements and garages, especially during the cold months. A study of this species done on Beaver Island, Michigan, showed that they prefer human-built structures

Fig. 83. Eastern Milksnake (Lampropeltis triangulum triangulum) from Clinton County, Michigan. Photograph by James H. Harding.

In Michigan I have observed the first active Milksnakes in April and the last in October. Ernst and Ernst (2003) reported that most of this snake’s aboveground activity occurs from April through June with a second peak from August to October. They stated that after spring emergence, this species basks near its place of hibernation before moving to summer feeding areas. They also mention that this snake is often found in more upland situations in the spring and fall (when the species is presumably moving out from or back to its hibernating sites) than in the summer. I have noticed that in the summer, Eastern Milksnakes in Michigan seem to become more nocturnal in their movements. Eastern Milksnakes generally hibernate from October to April in Michigan and often hibernate communally. Hibernating sites include rodent burrows, rock and soil crevices, cavities under rotted stumps, road embankments, old wells, and crawl spaces and house foundations (Harding 1997). Fitch (1999) studied the movements of forty-one marked Lampropeltis triangulum in several sites in Kansas for ten years. The farthest the snakes ranged were 504, 457, and 337 m (1,653, 1,499, and 1,105 ft.). This

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The Amphibians and Reptiles of Michigan

movement was interpreted as probably being shifts in home range. Many times individual Milksnakes returned to shelters they had previously used. For instance, a female that was captured six times within three years had returned to the same site three times. A male captured seven times within four years was found at the same site four times. Shaw (1951) observed that, like other male Kingsnakes, Lampropeltis triangulum has a male combat dance that establishes dominance. Reproduction and Growth The smallest known mature females of the Eastern Milksnake are probably about 397 mm (15.63 in.) in total length (Wright and Wright 1957). C. H. Ernst reported on two matings of captive Eastern Milksnakes (Ernst and Ernst 2003). The male would actively seek the female by following her scent trail with much tongue flicking. When the female was found, the male would place several folds of his body on her back, seize her neck with his mouth, and then perform jerky undulations of his body. He would then twist his tail around the tail of the female while he looked for her vent. Once her vent was found, he would insert one of his hemipenes and straighten his tail so that it would lay alongside that of the female. The female would usually raise her tail when penial insertion was made. The females in both instances remained calm during both courtship and copulation. The two copulations that Ernst monitored lasted thirtyfive and forty-four minutes, and the entire sequence of courtship and mating lasted fifty-three and sixty-eight minutes. The gestation time is about thirty to forty days. Henderson et al. (1980) reported that several females will lay their eggs at the same site. Dyrkacz (1977) reported that seventy-nine of eighty Eastern Milksnake eggs from Illinois were fertile and that fifty-seven of them hatched. Harding (1997) reported that very young Eastern Milksnakes are colored more brightly than adults and possess black-bordered red or maroon blotches on a pale gray background. At hatching time they range in length from 168 to 280 mm (6.6–11.0 in.). Of interest is that the hatchlings of the banded and tricolored subspecies of Lampropeltis triangulum are colored and marked like the adults of their particular subspecies. The rate of

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growth in Eastern Milksnakes is rapid in hatchlings and juveniles, slows when maturity is achieved, and is slowest in adult snakes. Eastern Milksnakes in Illinois grew from an average total length of 238 mm (9.37 in.) as hatchlings to an average of 260 mm (10.24 in.) in a month’s time (Dyrkacz 1997). Eastern Milksnakes appear to be long-lived animals, as a female wild-caught specimen lived in the Philadelphia Zoo for an additional twenty-one years and four months. Diet Brown (1979) recorded from his research that small mammals made up 79 percent of the volume and 68 percent of the frequency of food eaten by Eastern Milksnakes. More than 59 percent of the small mammals eaten were young. Birds made up 12.7 percent of the food volume (19 percent frequency), and reptiles made up 8.1 percent of food volume (12.4 percent frequency). Broad catagories of food consumed by L. triangulum, condensed from a very specific list compiled by Ernst and Ernst (2003), are as follow: shrews, mice, voles, a variety of birds, snakes (including venomous species), frogs, toads, salamanders, minnows, slugs, and insects. Milksnakes have a blood serum that has venomneutralizing properties (Weinstein et al. 1992), thus it is not unusual that even venomous pit vipers are eaten by this species. Eastern Milksnakes may either forage for their prey or lie in ambush for it. It is a constricting species that grabs its prey in its mouth and then hastily wraps coils of its body around it. The prey suffocates in these coils more rapidly than might be expected. Items such as small reptile eggs, suckling mice, or small species of shrews are quickly swallowed with no attempt at constriction. I am not aware whether Eastern Milksnakes catch small prey inside tunnels, but I would not be surprised to learn that this happens. Compared to many other constricting snakes in the United States, Eastern Milksnakes have a relatively slim head and body, which dictates the smaller size of prey eaten. Predation and Defense In Michigan and the Great Lakes region, few data are available about the predators of Eastern Milksnakes. They are likely eaten by various predaceous mammals such as raccoons, skunks, and opossums as well as various predatory

2. Species Accounts

birds and snakes, such as the Blue Racer. Probably the best defense this species has is its secretive behavior. Interaction with Humans Especially in the early spring and late fall, juvenile Eastern Milksnakes, and sometimes adults, regularly turn up in basements of houses and other buildings in Michigan. When people approach these snakes, the reptiles coil up, strike out freely, and vibrate their tails. This defensive posture sometimes gets them killed by frightened property owners who think the vibrating tail indicates a venomous species. If picked up by humans, large Eastern Milksnakes evince an odd defensive behavior compared to other snakes in Michigan. They appear to be calmly exploring the hand or arm of their captor with their flickering tongue, when, without warning, they start to chew on a finger or loose part of skin on the wrist or arm. If the snake is wrenched free, rather profuse bleeding may occur. But as far as I am aware, all of the tiny punctures heal very rapidly. Most of my Michigan herpetological colleagues and I have all experienced this annoying surprise. The Eastern Milksnake actually does a service to the human community by significantly reducing rodent pests wherever they live. Behavioral Characteristics For the behavioral characteristics of L. triangulum, see the sections “Habitat and Habits,” “Reproduction and Growth,” “Diet,” “Predation and Defense,” and “Interaction with Humans” in this account. Population Health Harding (1997, 324) stated that “while intense agricultural or urban development has surely eliminated some local populations, Milk Snakes remain common in many farming and suburban areas.” I have noticed somewhat of a decline in this species in Michigan during the last few years, but the reason may be the drier than usual conditions in the state during this period. The Eastern Milksnake is not presently a listed species in Michigan. General Remarks The Milksnakes get their common name from the belief that they suck milk from the udders of cows, perhaps

because they are frequently found in or around barns. This is false folklore. A Milksnake’s teeth and jaws are not constructed to do such sucking, and besides, any cow that I have ever met would not stand for such toothy abuse. In Indiana, the Eastern Milksnake is sometimes called a House Snake or Spotted Adder (Minton 2001), and these names are sometimes heard in Michigan as well.

Nerodia erythrogaster neglecta (Conant 1949) Copper-bellied Watersnake Identification The Copper-bellied Watersnake is a large, heavy watersnake that usually has a uniform color of black, gray, or brown on its back and sides. Some individuals, however, retain a little of the blotched pattern that occurs in hatchlings or juveniles of this species. The scales on the lips are red or orange and have dark edges. The chin and throat are light in color. The belly of this snake is unmarked (plain) and ranges from pale orange to red or copper. The scales are heavily keeled, and the anal plate is usually divided. Harding (1997) gave the total adult length of the Copper-bellied Watersnake as 670 to 1,415 mm (26.4–55.7 in.). Males are usually smaller than females but have longer tails. General Distribution Nerodia erythrogaster neglecta occurs in small, isolated populations in northwestern Ohio, southern Michigan, and northern Indiana. More continuous populations of this snake live in southwestern Indiana along with adjacent populations in Illinois and Kentucky. Another isolated cluster of these Watersnakes occurs in southeastern Indiana (Minton 2001, 272, map). Intergradation with the subspecies N. e. flavigaster occurs to the south and west. Michigan Distribution The Copper-bellied Watersnake has spotty occurrence in the lowest three tiers of counties in Michigan. It has been recorded from Cass, St. Joseph, Branch, and Hillsdale counties in the lowest tier, from Kalamazoo County in the second tier, and from Eaton and Oakland counties in the third tier.

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The Amphibians and Reptiles of Michigan

FIG. 84. Copper-bellied Watersnake (Nerodia erythrogaster neglecta) from east-central United States. Photograph by James H. Harding.

Geographic Variation Too few Michigan specimens of Nerodia erythrogaster neglecta have ever been available to study geographic variation in populations of this subspecies. Three other subspecies are recognized in N. erythrogaster in the United States, though, and these are N. e. erythrogaster (Forster 1771), the Red-bellied Watersnake; N. e. flavigaster (Conant 1949), the Yellow-bellied Watersnake; and N. e. transversa (Hallowell 1852), the Blotched Watersnake (Crother 2008). Two other subspecies occur in Mexico. Habitat and Habits In Michigan, Copper-bellied Watersnakes generally prefer lowland areas where shallow standing water is associated with deciduous trees. Harding (1997) reported that in spring these Copper-bellies often inhabit shallow ponds and buttonbush swamps where they frequently bask on various objects. As the weather gets warmer and these aquatic situations begin to dry up, the snakes tend to migrate to more permanent waters, using relatively dry corridors for these travels. They become mostly nocturnal during hot weather. Compared to the other large watersnake that occurs in Michigan—Nerodia sipedon sipedon, the Common Watersnake—the Copper-bellied Watersnake spends considerably more time in dry places. Relative to the Great Lakes region, Harding (1997, 260) stated that “these snakes are typically dormant from late October or November until sometime in April, usually seeking shelter in burrows or debris piles that are higher

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than the nearby wetlands. Occasional individuals will overwinter in crayfish burrows or other lowland sites but risk death by flooding if water levels rise during dormancy.” Kingsbury and Coppola (2000) traced Copper-bellied Watersnakes implanted with radios in southern Indiana and western Kentucky and found that these snakes did not make long migrations to upland hibernacula but hibernated individually in or adjacent to their wetland habitats. They usually used empty crayfish burrows or rotting stumps in wet forests in lieu of nearby uplands less than 20 m (65.6 ft.) away. The snakes tended to use the same site in the ensuing years. Reproduction and Growth Courtship and copulation of Nerodia erythrogaster usually occurs from April to mid-June in the United States. C. H. Ernst described their courtship and mating (Ernst and Ernst 2003). During courtship the male follows the female with much tongue flicking as he apparently follows the trail of her scent. He finally crawls alongside her and then loops his body back and forth along her back. He presses her head to the substratum with his head and attempts to arrange his tail beneath hers so their vents are aligned. If the female is ready for copulation, she will slightly raise her tail. The snakes either lie still or intertwine during the act of copulation. Conant (1965) reported that Nerodia erythrogaster in Mexico may store usable sperm for almost two years.

2. Species Accounts

The gestation period is thought to last about three to four months, and the young are born from August to October. The young are much more strongly patterned on the back, sides, and belly than are the adults. At birth, Copper-bellied Watersnakes average from about 210 to 270 mm (8.3–10.6 in.) in total length. Very little information is available about their growth pattern. Conant and Downs (1940) provided some information about the growth rates of twenty captive hatchlings of the Copper-bellied Watersnake. These animals were born on September 5 and were fed a diet of chopped fish. By the following May, only three had survived. At birth they averaged 263 mm (10.35 in.) in length. On December 9 they averaged 259 mm (10.2 in.). On April 5 they averaged 307 mm (12.1 in.), and on June 13 they averaged 332 mm (13.1 in.). On the following May 2, the three surviving snakes averaged 420 mm (16.5 in.) in length. Diet Harding (1997) stated that most reports on the diet of the Copper-bellied Watersnake in the Great Lakes region show that these snakes feed mainly on amphibians and crayfish, and that this may reflect its habit of living in shallow ponds and swamps where fishes are rare. Relative to the food of Copper-bellied Watersnakes in Indiana, Minton (2001, 273) stated that “food items recorded for wild-caught Indiana snakes include frogs, tadpoles, salamanders, and a crayfish. This may reflect the preference of the Copperbelly for temporary waters where fish are uncommon. The snakes eat fish readily in captivity.” Although it appears that N. erythrogaster usually actively pursues its prey, Gillingham and Rush (1974) found these snakes in streams using their tail to grip rocks in such a way that their head faces into the current, and in this posture, they hold their mouth agape. This behavior is called “open-mouthed foraging.” Predation and Defense A list of the known predators of Nerodia erythrogaster is noted by Ernst and Ernst (2003). Those on the list that occur in Michigan include snapping turtles and largemouth bass. Humans are undoubtedly the worst enemy of this species in Michigan and probably everywhere else they occur. Humans not only have destroyed the habitats of these snakes, but they shoot

them, run over them with cars and trucks, and beat them to death with anything handy. If this large watersnake is given half a chance, however, it will crawl away or dive into the water to escape its antagonist. But if cornered, this snake will bite vigorously and spray musk as it thrashes around. In July 1946, while at Camp Riverdale, Indiana, Paul Coutz and I came upon a very large Copperbellied Watersnake basking near a pool cut off from the Muscatatuck River. The big snake tried to escape by crawling into the pool (which, by the way, had entrapped some catfish and large minnows we had caught the day before), and I made a lunge for the animal, grabbing it by the end of the tail. As I tried to pull the snake out onto the bank, it spun around rapidly, an inch or two of twitching tail breaking off in my hand. The snake hid somewhere on the bottom of the pool, and we were not again able to see the creature, even after fifteen or twenty minutes of waiting. The spinning behavior saved the “copperbelly” from ending up in the snake cage Coutz had hidden under his bunk in the church camp dormitory. Interaction with Humans Unfortunately, most interactions with humans in Michigan end up in the death of the Copper-bellied Watersnake. As for the Eastern Hog-nosed Snake, public education is essential for the conservation of this animal in the state. Preserving large blocks of habitat where this snake is known to occur is important because Copperbellied Watersnakes migrate between shallow wetlands and permanent water situations along upland corridors (Harding 1997). Population Health This snake is so rare in Michigan that it is listed as Endangered by the MDNR and is protected by law. Any sightings of this animal should be reported to the MDNR Wildlife Division in Lansing. Finding a new population of Copper-bellied Watersnakes in the state will make you an instant hero to any herpetologist in the Great Lakes region. General Remarks It is interesting to note that Ruthven et al. (1928) were unaware that this snake occurs in Michigan.

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The Amphibians and Reptiles of Michigan

Nerodia sipedon sipedon (Linnaeus 1758) Common Watersnake Identification The Common Watersnake (often called the Northern Watersnake) is a rather large, darkcolored snake that is usually found in or near water. The background color is gray, brown, or tan and can be very dark in old individuals. On the back and sides is a variable pattern of dark or reddish-brown crossbands and blotches. The older the snake, the duller the pattern becomes, so that sometimes elderly individuals in the field can appear to be solid black or brown. The light-colored belly is usually marked with a pattern of reddish-brown half-moon shapes. The scales are heavily keeled, which tends to add to the dull appearance of the older snakes. The total length of the adults in the Great Lakes region ranges between 610 and 1,405 mm (24.0–53.3 in.) (Harding 1997). Males of the Common Watersnake are smaller than the females and have longer tails. I believe the average size of Nerodia sipedon sipedon in southern Michigan has become smaller than it was during the 1960s because specimens much over a yard long are now difficult to find. General Distribution The Common Watersnake occurs from eastern Maine west to Nebraska and parts of eastern Colorado, south to Oklahoma and Arkansas, and east to Virginia and North and South Carolina. In the southern part of its range, the Common Watersnake intergrades broadly with the Midland Watersnake (Nerodia sipedon pleuralis), which ranges southward to the Gulf Coast of Florida and Mississippi. Michigan Distribution The Common Watersnake has been recorded in Gogebic and Ontonagon counties in the extreme western tip of the Upper Peninsula; it has not been recorded in Keweenaw, Houghton, Baraga, Iron, Marquette, and Dickinson counties to the east, but it has been recorded from the remaining Upper Peninsula counties farther eastward. Probably because of its swimming ability, the Common Watersnake is found on a relatively large number of Michigan islands, including Drummond

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and Bois Blanc, and the Charity Islands. It has also been recorded from Beaver, Garden, High, Hog, North Fox, Squaw, and Whiskey Islands in the Lake Michigan Archipelago. The Common Watersnake is recorded in most of the counties in the Lower Peninsula except for some in the thumb area and bordering Saginaw Bay. These are Arenac, Bay, Tuscola, Genesee, Sanilac, and St. Clair counties. This snake also has not yet been recorded in Gratiot County. Common Watersnakes probably occur in most or all of these counties. Geographic Variation I am not aware of any distinct populations of the Common Watersnake in Michigan. Three other subspecies of Nerodia sipedon are known, all of them within the United States. These include N. s. insularum (Conant and Clay 1937), the Lake Erie Watersnake; N. s. pleuralis (Cope 1892), the Midland Watersnake; and N. s. williamengelsi (Conant and Lazell 1973), the Carolina Watersnake.

FIG. 85. Common Watersnake (Nerodia sipedon sipedon) from Barry County, Michigan. Photograph by the author.

Habitat and Habits The Common Watersnake is ubiquitous in its aquatic habitats in Michigan, occurring in bays in the Great Lakes; bays around and inland aquatic situations on Michigan islands; and in and around lakes, ponds, pools, impoundments, swamps, marshes, bogs, rivers, and streams (even relatively swift ones) on the mainland. Permanent aquatic situations are favored. In Michigan, Common Watersnakes usually emerge from hibernation in April (probably as late as May sometimes in the UP) and remain active until October. Most activity normally takes place between April and August. Hibernation

2. Species Accounts

spots can include the foundations of bridges, beaver lodges, muskrat burrows, vole tunnels, crayfish burrows, and even logs and stumps. Several individuals often share a hibernating site. I once found several Common Watersnakes in a large rotting stump near a tiny stream in a farmer’s pasture near Indianapolis in very early April in 1944. In Michigan, Common Watersnakes often bask in bushes next to water, or on banks or patches of low grass exposed to the sun on the shore. They are quick to plunge into the water when disturbed, but M. M. Hensley and I have both noticed that after they have swum away for ten or twenty yards, they usually change course and come back to, or very near, the same basking site. Common Watersnakes may move away from their usual aquatic residence from time to time (see “Reproduction and Growth”). Fitch (1999) reported that 8.2 percent of N. s. sipedon that normally inhabited a Kansas pond were found in fields away from the pond; 6.0 percent were found along a small creek or its diversion that drained the pond; 6.0 percent were found at faraway ponds or streams; 4.7 percent were found on roads; and 2.8 percent were found during the fall and spring in upland outcrops where they hibernated. The greatest straight-line distances recorded for this pond population were from 1.15 to 1.73 km (.71–1.07 miles). Fitch also found that movements greater than 1 km (0.62 miles) were made by both males and females, and that these movements were made in almost all compass directions. Nerodia sipedon has homing ability, and Newcomer et al. (1974) have demonstrated that this species is capable of sun-compass orientation. Common Watersnakes are excellent swimmers. They swim with only their heads showing above the surface, although in calm water the slightly submerged body makes a characteristic trail above. These snakes can forage underwater, poking about among rocks, rubbish, and aquatic vegetation. They can remain submerged for more than sixty-five minutes (Ferguson and Thornton 1984), but I have never seen them remain underwater for more than a few minutes in Michigan. I recently saw one swimming along in the water holding a stiff and obviously dead fish, either a pumpkinseed or a bluegill (or a hybrid between the two), in its mouth. This was in a flooded area near Ovid Lake, several miles from

Lansing. When this animal became aware of my presence, it turned and swam laterally away from me. Reproduction and Growth Feaver (1976) reported that a female Michigan Common Watersnake was mature at a snout-to-vent length of 475 mm (18.7 in.) and that males mature at a slightly smaller snout-to-vent length. The breeding season probably occurs mainly in May or June in Michigan, most mating taking place during the daylight hours. Males look for females, possibly by following pheromone trails (Scudder et al. 1980). The courtship and mating of Common Watersnakes is similar to that of the Copper-bellied Watersnake. When a female is found by the male N. sipedon, he examines her by flicks of his tongue, lines up his body beside her and rubs against her, puts his head on her back and rubs her back with his chin, moves his body forward as he jerks it spasmodically, coils around the female and seeks her vent with his tail, and finally inserts one of his hemipenes in the vent. The whole sequence sometimes takes as long as two or three hours. Pregnant female Common Watersnakes often move great distances before giving birth to their offspring. Meyer (1992) documented that Common Watersnakes residing on the Lake Michigan shoreline move as much as 1 km (.62 miles) inland from the lake to give birth to their young, returning to their normal home area following this journey. The early growth of hatchling Nerodia sipedon is fast but slows as the snakes age. Fitch (1999) found that in Kansas, first-year young Common Watersnakes averaged 187 mm (7.36 in.) in snout-to-vent length in September. In October they averaged 197 mm (7.76 in.), and the next April they averaged 200 mm (7.87 in.). By July they averaged 289 mm (11.38 in.) in snout-to-vent length. Diet Common Watersnakes feed on aquatic vertebrates that inhabit their home range. Their foraging behavior is dependent on their body temperature, and that dictates when they successfully hunt for food. In northern Lake Michigan, snakes foraging in the lake will do so after basking to warm up and will stay in the water until their body temperature falls to about 16ºC (62ºF), at which point they will search for warmer water. These snakes tend to shuttle between warm and cold water to

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maintain a temperature appropriate for efficient foraging (Hansknecht 2003). The most comprehensive food study of the Common Watersnake in Michigan was done by Lagler and Salyer (1945). They examined a total of 302 specimens, mainly from several natural habitats, including trout streams and trout-rearing stations, mainly in the Lower Peninsula. Of the collections made, 114 of the snakes did not contain food, so the data were interpreted from the stomach analysis of 188 specimens. Their list of food items recovered from natural habitats in Michigan includes the following animals, most of them fishes: sunfish, bluegill, northern brown bullhead, madtom, northern common shiner, blackfin shiner, northern blacknose shiner, one undetermined shiner, hornyhead chub, northern creek chub, bluntnose minnow, one unidentfied cyprinid, mudminnow, johnny darter, Great Lakes muddler, eastern burbot, Leopard Frog, Green Frog, undetermined frog, unidentified salamander, Common Mudpuppies, and the traces of one small rodent. The percentage of frequency of occurrence of broad categories of food items in this lot was: Food Percentage Forage fishes 44.4 Frogs and salamanders 33.3 Other fishes 16.7 Game and pan fishes 11.1 Unidentified fish remains 11.1 Rodent traces 5.6 When they examined 106 Common Watersnake stomachs from trout streams, they found that only 6 percent of these snakes had eaten trout. Other fishes made up 86.7 percent of the diet of these snakes, and frogs and miscellaneous invertebrates made up 6.6 percent. A study on Common Watersnake foraging in northern Lake Michigan showed that more than 80 percent of their diet was composed of mottled sculpin, Cottus bairdii, and that these snakes foraged more often in habitats possessing a higher density of this preferred fish prey, thus showing that they conduct optimal foraging behavior (Carbone 1993). Harding (1981) reported that in Minnow Lake in Oakland County, Michigan, he observed a Common

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Watersnake feeding on a fish that was in an advanced state of decomposition. The snake had encountered this fish dead, floating on the surface of the water. The fish was covered with a whitish, cottony, fungus-like growth. The swallowing process lasted about five minutes. Predation and Defense Ernst and Ernst (2003) provided a long list of animals that are known or suspected of being predators of young and adult Nerodia sipedon. The listed predators likely to prey on Common Watersnakes in Michigan are pike, bullheads, bass, bullfrogs, snapping turtles, Blue Racers, Copper-bellied Watersnakes, rails, bitterns, egrets, herons, vultures, hawks, gulls, raccoons, mink, and skunks. When alarmed, the first defensive response of Common Watersnakes is to escape, either by crawling away when on land, or diving into the water. I have noticed that in early spring, while basking, these snakes are much slower in their responses than they are when the weather warms up in late spring. Weatherhead and Robertson (1992) noted that both defensive behavior and escape velocity in Common Watersnakes are correlated with body temperature. When cornered or captured by hand, there is no more wildly defensive snake in Michigan than Nerodia sipedon. It flattens both its head and body and strikes repeatedly, sometimes chewing the skin where it bites, but other times jerking its head backward and tearing the skin of its antagonist. If gripped by a human or predator, the snake expels a vile-smelling musk onto its captor by slapping its tail around vigorously. Everywhere I have lived, I’ve met many people who think this snake is venomous, and Michigan is not an exception. Ruthven et al. (1928, 105) in a footnote regarding the Common Watersnake, stated it is “often known as the Moccasin or Water Moccasin, although this name belongs properly to a venomous form, Agkistrodon mokasen, not found in Michigan.” These misnomers are still used by a few people in the state. Interaction with Humans Most interactions between humans and this snake that I have witnessed are injurious or fatal to the snake. The greatly traveled Florida herpetologist Archie F. Carr pointed out to our ecology class that you can always tell when groups of people throughout the world are

2. Species Accounts

gathered or gathering to kill a snake. They hustle about looking for sticks to whack with and rocks to throw; others come to join the group, either watching intently or taking part in the ritual killing. In my herpetological career, I must say that I have seen more such gatherings associated with doing away with Nerodia sipedon than any other species of snake within its range. I would be embarrassed to relate how many times I have been bitten and sprayed by this snake while I was trying to remove it from a road or whisk it away from people intent on killing it. The good news is that I never had an unpleasant reaction from one of the bites, other than some bleeding from the small pin pricks I received, and these always healed quickly. The Common Watersnake is not considered venomous by Ernst and Ernst (2003). The fact that this snake is not harmful to trout and other game fishes (Lagler and Salyer 1945) and has instead been seen eating dead fish is certainly a plus on its behalf. But a word of warning: if you make a seawall out of piles of boulders to protect your lake property against erosion, you are likely to have Common Watersnakes around, whether you like them or not. Behavioral Characteristics For the behavioral characteristics of Common Watersnakes, see the “Habitat and Habits,” “Reproduction and Growth,” and “Predation and Defense” sections of this account. Population Health Common Watersnakes are still common in many areas of Michigan and are not protected by law in the state. However, shoreline development coupled with unnecessary persecution of this snake has led to its extirpation in some places. General Remarks Humans are the worst enemy of Common Watersnakes in Michigan. I hope public education programs will be successful in making people aware of the important place in the ecosystem of this interesting snake.

Opheodrys vernalis (Harlan 1827) Smooth Greensnake Identification The Smooth Greensnake is the only snake in Michigan that has an upper body and head that are entirely bright green. The head is slightly wider than the body and has yellowish or whitish lips and a yellowish chin and throat. The belly is ivory, white, or pale yellow. Rarely, specimens are bronze, light brown, or tan. The scales are smooth, and the anal plate is divided. The total length of adults ranges from 300 to 660 mm (11.8–26.0 in.) (Harding 1997). Males are smaller but have longer tails than females. General Distribution This snake occurs from Nova Scotia west to Saskatchewan, Canada, including western Minnesota, and south to northern Illinois, southwestern Ohio, and northwestern Virginia. Disjunct, probably relict, populations are known in Iowa, northern Missouri, North and South Dakota, Nebraska, northwestern Utah, eastern Wyoming, Colorado, New Mexico, the coastal Gulf area of Texas, and Chihuahua, Mexico. Michigan Distribution This beautiful species occurs in every county in the Upper Peninsula. It occurs on Drummond and Bois Blanc Islands as well as Beaver Island in the Lake Michigan Archipelago. Opheodrys vernalis is widespread in about the upper half of the Lower Peninsula, but it is relatively rare in the bottom half where there are only scattered records except in one cluster of adjacent counties in southeastern Michigan. These counties are Livingston, Oakland, Washtenaw, and Jackson. Geographic Variation As far as I know, no distinct populations of this species exist in Michigan. At the time of this writing, no subspecies of Opheodrys vernalis are recognized (Crother 2008). Habitat and Habits In Michigan, the Common Greensnake is almost always associated with grassy areas, usually moist ones. They

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may be encountered in meadows, old fields, pastures, road rights-of-way, and in open deciduous or pine woodlands and their ecotones (borders). Greensnakes are usually encountered on the ground and tend to hide beneath logs, bark, piles of leaves, or human debris such as tar paper, flat boards, rags, or pieces of boxes. Ruthven et al. (1928) reported that this snake may climb small shrubs.

FIG. 86. Smooth Greensnake (Opheodrys vernalis) from Clare County, Michigan. Photograph by James H. Harding.

Smooth Greensnakes are active from May to September in most of Michigan. In the southeastern part of the Lower Peninsula it may emerge in April and not hibernate until October. Opheodrys vernalis often hibernates in ant mounds. Carpenter (1953) found one alive in an ant mound hibernaculum in Washtenaw County at a depth of 510 mm (20.1 in.). This snake had been observed the previous year emerging from the site on May 2. Smooth Greensnakes have also been found in other types of hibernacula such as rock piles and mammal burrows. This species may hibernate with other species of snakes, and C. H. Pope (1944, 169–70) reported that “a hibernating colony of 8 plains garter snakes, 101 red-bellied snakes, and 148 green snakes was taken from an ant hill in southern Manitoba, a region in which the eastern and western green snakes intergrade. The ant hill, a flat mound about thirty-six inches in diameter and six high, was located among hazel and hawthorn scrub at the edge of a small opening

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surrounded by oak and aspen woods. Not far away were willow swamps and muskegs. The snakes were distributed from near the surface to depths of 57 inches, the deepest ones being partly submerged in water.” This aggregation was first reported by Criddle (1937). Relative to daily activity of this species in Michigan, almost all Smooth Greensnakes I have seen have been crossing back roads with grassy shoulders. Almost all were in the northern part of the Lower Peninsula or in the Upper Peninsula. Usually I have seen them between 10 a.m. and 4 p.m. When I left my car to catch and examine them, they would try to wriggle out of my hand and would release some musk, but none ever attempted to bite. Years ago I attempted to keep two of them in captivity, but they both refused all types of small live insect and spider food that I offered. When they were not hiding under objects that I had given them to retreat under, they were very nervous and appeared to be constantly on the move until they retreated into their hiding places again. I released them in the same area I found them after only two weeks. The only Smooth Greensnake I have found in the woods (in a stand of white pine, aspen, and pin oak) was one that emerged from a pile of leaves by a foot trail and moved away very rapidly. In north-central Illinois I often found Smooth Greensnakes under piles of cut grass on road shoulders. This was in an area of intensively cultivated farmland where the road rights-of-way appeared to be the only available habitat. I never saw any of these snakes crossing the road in this part of Illinois and never found any in the very few woodlots that occurred in the area. In Wisconsin, Vogt (1981) found this species crossing roads at night during warm summer rains. Reproduction and Growth Female Smooth Greensnakes reach sexual maturity at total body lengths as short as 280 mm (11.0 in.), and males may be sexually mature at total body lengths as short as 300 mm (11.8 in.) (Wright and Wright 1957). Very little is known about the courtship and breeding of this species. Ernst and Ernst (2003) found a pair of these snakes copulating in Pennsylvania on April 15. Blanchard (1932) reported that nesting occurred from June 9 to August 29 in Michigan and that females may deposit two clutches each season. Snakes from populations in the south laid their eggs in June and July

2. Species Accounts

but oviposition in the north took place from late July through August. Nest sites were in mammal burrows, piles of decomposing plant material, rotting logs and stumps, and sawdust piles. Females shared nesting sites. The eggs may be partially incubated in the female, as the eggs are in an advanced stage of development when they are laid. This may be an adaptation in the Smooth Greensnake for a northern existence. Harding (1997, 302) reported that “one anecdotal account suggests that the young [of Smooth Greensnakes] may occasionally be born alive.” The eggs of this snake are laid in loose clumps, and each one has a thin shell and elongate shape. Twentyone measured eggs had a mean length of 21.1 mm (.83 in.). The eggs hatch mainly in late August and early September, and the hatchlings are differently colored than the parents, being gray to olive brown. The young are tiny and average 133 mm (5.24 in.) in total length. Growth data are lacking for this species (Ernst and Ernst 2003). I would venture to say that this is probably because this species is so difficult to maintain in captivity. Diet The diet of Opheodrys vernalis consists mainly of insects such as ants, beetles and their larvae, flies, crickets, grasshoppers, and caterpillars. Other arthropods such as centipedes, millipedes, harvestmen, and spiders are also eaten. Occasionally these snakes will feed on earthworms, slugs, and even the odd salamander. Uhler et al. (1939) examined stomachs of Virginia Smooth Greensnakes, which contained by volume: Percentage Food Caterpillars 36.8 Spiders 31.8 Grasshoppers 20 Ants 10 Slugs and snails 1 Fly larvae 0.4 Similarly, in northern Michigan smooth-bodied caterpillars (predominantly in the family Noctuidae) made up between 40 percent and 50 percent of the Smooth Greensnake diet, while opiliones (daddy longlegs) became more numerous later in the season when the noctuid larvae were not as abundant following their metamorphosis (Waters 1993).

Predation and Defense The predators of this species are poorly documented. Relative to the Great Lakes region, Harding (1997) stated that Smooth Greensnakes are eaten on occasion by hawks and other birds, various mammals, and reptileeating snakes. The fact that Smooth Greensnakes blend in very well with their grassy habitat is probably the best defense for this little snake. Opheodrys vernalis can crawl very rapidly from an exposed to a grassy situation. Unfortunately, they appear to get poor traction on smooth roads, where they tend to wriggle ineffectively, “getting nowhere fast.” Smooth Greensnakes do not bite when grabbed by humans, but they often exude a smelly musk on the hand that seizes them. Interaction with Humans As for the Northern Ring-necked Snake, most people in Michigan regard the Smooth Greensnake as a harmless, pretty little creature that they leave alone, or are even happy to have on their property. My father, who had an intense dislike for most snakes, allowed that Greensnakes should probably be left alone. Behavioral Characteristics For the behavioral characteristics of Smooth Greensnakes, see the sections “Habitat and Habits,” “Reproduction and Growth,” and “Predation and Defense.” Population Health Opheodrys vernalis is not protected by Michigan law, but Harding (1997, 302) stated that “decreasing numbers and local extirpation of the Smooth Green Snake, particularly in the southern Great Lakes basin, have been blamed on the conversion of its habitat to intensive agricultural use, and on the widespread application of pesticides.” I accept the pesticide hypothesis, as Minton (2001, 298–99) stated that “the food habits of both Indiana Green Snakes makes them vulnerable to toxic pesticides. On June 3 in a section of northwestern Indiana that had been heavily sprayed with insecticide, I collected two Smooth Green Snakes. One was barely alive; the other appeared normal but died two weeks later.” I discovered that Smooth Greensnakes were not uncommon in some areas of north-central Illinois in the early 1960s, even in areas where corn and soybeans

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were planted to within a few feet of the edge of the road. Thirteen-lined ground squirrels were abundant in these areas, and it seems possible that the snakes sheltered and hibernated in the numerous burrows of these mammals. General Remarks Smooth Greensnakes appear to me to have possibly different behavioral attributes in different regions. In northern Michigan, the individuals I have observed, which frequented edges of deciduous and broadleaf forests on sandy soil, are smaller, more gracile, and more nervous than the Greensnakes I have observed in the essentially treeless central Illinois black-soil prairies.

Pantherophis spiloides (Duméril, Bibron, and Duméril 1854) Central Ratsnake NOTE: The Central Ratsnake (Pantherophis spiloides) was long known as the Black Ratsnake (Elaphe obsoleta obsoleta). For the complicated history and rationalization of this major name change, see Burbrink (2001); Burbrink et al. (2000); Crother (2008); and Utiger et al. (2002). Identification The Central Ratsnake is the largest snake in Michigan and in the Great Lakes region as well. Adults of this species are mainly black, but sometimes very dark brown individuals are seen. The mouth, chin, and throat are white. Most adults have white, yellow, or orange flecks scattered on the body, especially between the scales. This flecking is a remnant of the blotched color pattern that occurs in hatchlings and juveniles. The head is distinct from the body and somewhat flattened. The body is somewhat rectangular in cross section, a trait that is found in other Ratsnakes of the genus Pantherophis but is quite unlike the rounded cross-sectional shape of the Racer, for example. The belly has a whitish or yellowish background color that bears a dark checkerboard pattern on the front portion of the body; at the middle of the body and on the tail, the pattern becomes obscured by brown or gray. The scales of the upper body are weakly keeled, and the anal plate is divided. Harding (1997) gave the adult total length as 1,000 to 2,565 mm (39.4 to 101.0 in.).

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General Distribution The suggested general distribution of the Central Ratsnake is from southwestern Wisconsin east through southern Michigan and southern Ontario to southern New York; south through Appalachia to Alabama; west through western Florida to southeastern Louisiana; and north through Mississippi, Tennessee, Kentucky, and southwestern Illinois (Burbrink 2001). Michigan Distribution The Central Ratsnake is absent from the Upper Peninsula and Michigan islands but occurs in roughly the southern half of the Lower Peninsula. Its range extends in the southwest as far north as Oceana and Newaygo counties and in the central and eastern part of Lower Michigan to Montcalm, Gratiot, and Saginaw counties. It has not been recorded in the thumb area except in Lapeer County and has also not yet been recorded from the counties bordering Saginaw Bay. Geographic Variation No distinct populations of Central Ratsnakes have been reported from Michigan, and no subspecies are presently recognized in the species Pantherophis spiloides. Habitat and Habits Central Ratsnakes are typically animals of deciduous woodlands. However, they sometimes wander out of the woods into open areas such as overgrown fields, and even marshes and swamps. During their wandering they may end up in or near barns, around old foundations, or even in or around large rubbish piles. They are the most arboreal reptiles in Michigan and sometimes climb as high as 12 meters (39.4 ft.) or more in trees, using their strong, flexible bodies along with their wide ventral surface to gain purchase on the limbs as well as the sides of fence posts and buildings. McAllister (1995) reported that in Ontario, Eastern Ratsnakes are found in marshes during the nesting season of birds. Also in reference to Ontario, Weatherhead and Charland (1985) stated that during the bird breeding season, these snakes preferred fields or the ecotones between fields. Oddly, Ruthven et al. (1928, 92) stated that “the writer has been unable to gather any data on the habitat of the pilot snake [an old common name for Central Ratsnake] in Michigan.” Minton (2001) stated that this species has

2. Species Accounts

Fig. 87. Central Ratsnake (Pantherophis spiloides). Photograph by James H. Harding.

been found in crevices just within the entrances of caves in Indiana. In the Great Lakes region these snakes tend to be active from late April through October (Harding 1997). Concerning the northernmost populations of Central Ratsnakes in Ontario, Weatherhead (1989) reported that their activity period may be as short as four or five months with at least seven months of hibernation. Hibernacula are sites such as mammal burrows, root systems, or deep rock crevices in the Great Lakes region. In general, Central Ratsnakes in the Great Lakes region have a tendency to hibernate with other large snakes, such as Racers. In the southern hilly section of Indiana, Minton (2001, 103) reported that “I have had several reports of hibernating snake aggregations found during quarrying, road building, and similar operations. In all, the Black Rat Snake [Central Ratsnake] seemed to be the predominant species and was usually associated with the Black Racer, Copperhead, and Timber Rattlesnake.” An old common name for the Central Ratsnake was “Pilot Black Snake” (e.g., see C. H. Pope 1944, 174), which is explained in Ditmars (1933, 175): “The name Pilot Black Snake comes from an erroneous idea; it is thought this serpent warns the rattlesnake in time of danger, leading the slower, venomous reptile to a safe retreat. The theory has probably arisen from the fact that the Pilot Black Snake frequents the same localities as the timber rattlesnake, the two species, in the Northern States, hibernating in the same dens.”

Fitch (1999) found that in a Texas Ratsnake population he had been monitoring for fifty years, there was no fidelity for particular hibernating sites. On the other hand, Ernst and Ernst (2003) found fidelity to particular hibernating sites by Eastern Ratsnakes in Virginia. Fitch (1963, 1999) reported that the average distance Texas Ratsnakes moved away from their hibernacula in Kansas was 384 to 403 m (418.6–439.3 yd.) in males and 362 m (394.6 yd.) in females. My very limited experience with Ratsnakes in Michigan has largely been with seeing the snakes in trees, probably because my mentor on the subject, Dr. M. M. Hensley, told me to look for them in trees. But I also saw many of these snakes on the ground along with a few in trees when I lived in Indiana. In the process of my catching these snakes on the ground, one Central Ratsnake disgorged a fully grown chipmunk, and another disgorged the remains of an American kestrel (see Minton 2001, 304). I have always thought the kestrel must have been dead when it was eaten by the snake because most of its disgorged remains consisted of feathers, but I could be very mistaken in that logic. I have never seen a Central Ratsnake in Lansing or East Lansing, Michigan, but I was given an unquestionable skin of this species that came from Grand Ledge, essentially a suburb of Lansing in Eaton County. Grand Ledge has exposed rock outcrops along the Grand River, which runs right through the town. The gentleman who brought in the skin told me that he had seen a very large black snake in or near the same tree several times. Central Ratsnakes are not only expert tree climbers but good swimmers as well and have been observed in the water and in trees surrounded by water (Ernst and Ernst 2003). Reproduction and Growth Male Central Ratsnakes engage in combat dances that establish their dominance. In this behavior, one male tries to pin the head or body of the other male to the ground. This is thought to be related to competition for mates. Gillingham (1980) described seven patterns involved in this behavior. In the Great Lakes region, mating of Central Ratsnakes takes place mainly in May or June. At least in Kansas, fall mating of Texas Ratsnakes may also occur (Fitch 1963, 1999). Mating may take place either on

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the ground or in trees (Padgett 1987). The following account of courtship and mating is mainly from Harding (1997), Johnson (1950), Kennedy (1978), Mansueti (1946), and Gillingham (1979). The male presses his chin on the female’s back and moves forward, aligning his body with hers and mounting by placing his body on her dorsum. Waves of contractions then move forward along the body of the male. At this time, he begins to exhibit tail-search copulatory attempts with his tail. He moves his tail under the female’s tail to attempt cloacal juxtaposition. Once juxtaposition is attained, one of his hemipenes is inserted. Copulation lasts about twenty minutes. With reference to the Great Lakes region, Harding (1997) reported that females lay their eggs in the latter part of June or in July. Central Ratsnake nest sites may be located in soil or leaf mold, rotting logs or stumps, manure or sawdust piles, or cavities under boards or rocks. Sometimes two or more females will share a nesting site. About a dozen eggs per clutch are laid. The eggs have an oval to almost round shape and flexible, granular shells that may stick to each other and form clumps. The eggs range in length from 35 to 55 mm (1.38–2.17 in.). Most hatchling Central Ratsnakes in the Great Lakes region emerge in late August or in September after an incubation period of about sixty to seventy-five days. The hatchlings of Central Ratsnakes differ from the adults in having a gray rather than black background color and being distinctly blotched. The mean length of the hatchlings is about 386 mm (15.2 in.) (Ernst and Ernst 2003). Central Ratsnakes tend to grow rapidly at first and then more slowly as they age. For instance, in Maryland the growth in male Ratsnakes slows greatly near 1,340 mm (52.8 in.) at about six to eight years of age. Growth of females of this species slows at about 1,250 mm (49.2 in.) (Stickel et al. 1980). Ratsnakes have lived more than twenty years in captivity; Fitch (1999) estimated the age of a marked individual in Kansas at twenty-one years. Diet All reports that I have read on the subject indicate that mammals and birds, usually in that order, are the most important items in the diet of Central Ratsnakes. Fitch (1963) found that mammals and birds made up about

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90 percent of the diet of Texas Ratsnakes in Kansas. Minton (2001) examined the stomachs of twentytwo Indiana Central Ratsnakes. Mammals were found in fourteen stomachs, and these remains represented wood mice, meadow voles, a house mouse, two young rabbits, a young squirrel, eight unidentifiable small rodents, and an unidentifiable insectivore. Eight of the stomachs contained birds or their eggs. The bird remains represented a mourning dove, a young chicken, a robin and its eggs, fledgling redwing blackbirds, a brood of house wrens, an unidentifiable bird, and two lots of unidentifiable eggs. Minton was generally unable to get hatchling Central Ratsnakes to feed on suckling mice, although juveniles would accept them readily. Both the hatchlings and juveniles would accept small hylid frogs and lizards. He reported that other than small, weak animals such as nesting birds, prey is killed by constriction. I am not aware of any specific food habit studies of Central Ratsnakes in Michigan. Predation and Defense Large adult Central Ratsnakes have few enemies other than humans with clubs and cars. Small adults, juvenile, and hatchling Ratsnakes, however, fall prey to several kinds of reptiles, including Copperheads, Racers, Kingsnakes, Whipsnakes, Coral Snakes, and Alligators. Mammal and bird predators include hawks, owls, shrews, raccoons, weasels, dogs and coyotes, domestic cats, and pigs (see Ernst and Ernst [2003] for a more detailed list). Fitch (1963) considered the red-tailed hawk to be an especially important predator of the Texas Ratsnake. He suggested that hawks may find these snakes by watching the reactions of small birds when a snake is nearby. For defense, Central Ratsnakes tend to either “freeze” or crawl away when approached by a potential enemy. If this snake is prevented from escaping, it usually coils and vibrates its tail; it may also strike out somewhat aimlessly, another warning signal. If grabbed by a predator or human, it will bite vigorously and exude a strong musk. Sometimes Central Ratsnakes will wrap themselves around part of an attacker’s body and constrict it (Meshaka et al. 1988). Interaction with Humans Central Ratsnakes are beneficial to humans because they reduce the number of rodent pests in fields, barns,

2. Species Accounts

and gardens. Harding (1997) stated that the fact that Central Ratsnakes also eat birds may be objectionable to some people, but the impact on bird numbers by this snake species is insignificant compared to that of more abundant predators. Minton (2001) mentioned that this species is called the “Cow Snake” by people throughout much of southern Indiana and Kentucky. It is widely believed to be a cow sucker and milk stealer, probably because it is often found in pastures and barns. “Chicken Snake” is a name frequently given to it in the Evansville area and southward. I am not aware of any vilifying common name applied to this snake by Michiganians. Central Ratsnakes have lost quite a bit of woodland and woodland-edge habitats in Michigan to agriculture and urban expansion. These snakes could actually increase in number if some of the state’s woodlands were broken up a bit by “low-intensity” agriculture that would create edges and openings. Central Ratsnakes are unfortunately sometimes killed by people and are occasionally collected by reptile hobbyists. Behavioral Characteristics For the behavioral characteristics of Pantherophis spiloides, see the sections “Habitat and Habits,” “Reproduction and Growth,” and “Predation and Defense” in this account. Population Health The Central Ratsnake is considered to be a rare and declining species by the Wildlife Division of the MDNR and is listed as a Species of Special Concern. These snakes are thus protected by Michigan law. General Remarks Some farmers recognize the value of Ratsnakes, as Ernst and Ernst (2003, 122) explained: “When C. Ernst was at the University of Kentucky several local farmers came to him each year for excess rat snakes that they then released in their barns and corn cribs.”

Pantherophis gloydi (Conant 1940) Eastern Foxsnake (represented by dots in the Lower Peninsula only) NOTE: The Eastern Foxsnake, Pantherophis gloydi (Conant 1940), was long known as Elaphe vulpina gloydi and commonly called the Eastern Fox Snake. For the complicated history and rationalization of this major name change, see Burbrink (2001), Burbrink et al. (2000), Crother (2008), and Utiger et al. (2002). Both this species and Pantherophis vulpinus, whose account follows this one, are very closely related and may someday again be recognized as subspecies of the same species. Identification The Eastern Foxsnake (Pantherophis gloydi) and the Western Foxsnake (Pantherophis vulpinus) are separated from each other on the basis of two main factors. First, they are geographically separated, so at least for now they are unable to breed with each other in the wild. The Eastern Foxsnake occurs in the western part of southern Ontario, the eastern part of the Lower Peninsula of Michigan, and north-central Ohio. The Western Foxsnake occurs in the Upper Peninsula of Michigan and possibly the Manitou Islands (K. D. Bowen and J. C. Gillingham, pers. comm., 2009), northwestern Indiana, northern and south-central Illinois, and west to eastern South Dakota and Nebraska (see Conant and Collins 1998, 357, map). Second, in the Western Foxsnake, the large dorsal blotches of the body average forty-one in number. In the Eastern Foxsnake, the large dorsal blotches are larger and fewer, averaging thirty-four, and the head is likely to be somewhat red in color. Both the Eastern and Western Foxsnakes have the following characteristics that will help in their identification in Michigan, whether in the Upper Peninsula or the southeastern part of the Lower Peninsula. These are strikingly blotched snakes. The background color varies from light brown to shades of yellow. The blotches vary from black to brown. The head lacks bold markings and may be brown, reddish, or some color in between. The belly of these snakes is yellow and boldly checkered with black. These Foxsnakes have weakly keeled scales, and the anal plate is divided.

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The males and females of these species are difficult to distinguish from each other. The Eastern Foxsnake ranges from 900 to 1,705 mm (35.4–67.1 in.) in total length; the Western Foxsnake ranges from 900 to 1,550 mm (35.4–61.0 in.) in total length (Harding 1997). General Distribution The general distribution of both the Eastern and Western Foxsnakes are described in the previous “Identification” section. Michigan Distribution The Eastern Foxsnake has been recorded in eight counties in the eastern Lower Peninsula of Michigan, from the Ohio border north to the northern border of Saginaw Bay. The eight counties are Monroe, Washtenaw, Wayne, Macomb, St. Clair, Saginaw, Huron, and Iosco. Lee (2000b) reported that this species has not been reported from Huron County since 1936 and that the report from Iosco County needs to be verified since it appears to be outside of the natural range of the species. She reported that “these snakes have been documented along the shoreline of lakes Erie, St. Clair and Huron, as well as along the Raisin, Detroit, Clinton and Shiawassee rivers and their tributaries. A survey for the eastern fox snake in 1986 documented four main, isolated populations in southern Michigan, two in Monroe County along Lake Erie, one in St. Clair County along

Lake St. Clair, and one in Saginaw County associated with the Shiawassee River and its tributaries” (1). See also C. A. Weatherby’s survey report (1986) for more details about the distribution of Pantherophis gloydi. Thompson and Thompson (1912) reported that two Eastern Foxsnakes were killed on Charity Island, Huron County, by a Captain McDonald in about 1896, and that this was the only record of this species for the island. Charity Island is the largest of three small islands situated near the mouth of Saginaw Bay. Geographic Variation No distinct populations of the Eastern Foxsnake have been reported in Michigan. The same is true of the Western Foxsnake in the state. Habitat and Habits The most typical habitat of the Eastern Foxsnake in Michigan is the marshy open wetland along the borders of Lake Erie, Lake Huron, and Saginaw Bay. Pantherophis gloydi also may be found in associated river impoundments (Evers 1994). These snakes prefer areas that have herbaceous plants such as cattails. Sometimes they are found in vegetated dunes, or even in pastures and woodlots from time to time (Harding 1997). On the Lake Erie islands of Ohio, Eastern Foxsnakes occupy rocky areas and open woods (Lee 1999). Weatherby (1986) reported that Eastern Foxsnakes can be found

FIG. 88. Eastern Foxsnake (Pantherophis gloydi) Photograph by James H. Harding.

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basking on muskrat houses or artificially created structures, such as dikes or road embankments. He also stated that Eastern Foxsnakes could be found on roads at night after exceptionally hot days. Eastern Foxsnakes are generally active from midApril to late October, with a peak of activity in May and June (Evers 1994). They are generally diurnal during these months, but during very hot weather they may become more nocturnal. These snakes are good swimmers and can swim long distances across open water between islands (Harding 1997). Home range studies of this species are limited, but Rivard (1976) and Freedman and Catling (1979) have indicated that shifts of up to several hundred feet are not uncommon for individual Eastern Foxsnakes. Harding (1997) reported that this snake hibernates in abandoned mammal burrows or other situations that are frost free. Reproduction and Growth Eastern Foxsnakes probably breed annually at about two years of age (Evers 1994). The most active part of the breeding season is probably in June (Ernst and Ernst 2003). Little information about courtship and breeding in the Eastern Foxsnake is available, but more is understood about the Western Foxsnake (Barten 1992). Kile Kucher (pers. comm.) observed copulation in Eastern Foxsnakes in Shiawassee County and noted that the male bit the neck of the female during this interaction. It may be safe to assume this behavior is similar in these two closely related species. (See “Reproduction and Growth” in the following Western Foxsnake account.) An Eastern Foxsnake caught as an adult lived seven years, five months, and eighteen days (Snider and Bowler 1992). Diet Eastern Foxsnakes probably feed mainly on small mammals such as meadow voles and deer mice. Other vertebrates that are known to be eaten are bird eggs, nestlings, and occasionally adult birds (Lee 2000b). Earthworms, insects, and frogs are possibly eaten by young Eastern Foxsnakes (Harding 1997). Ruthven et al. (1928) stated that an Eastern Foxsnake taken in Huron County had eaten four young rabbits. Adult birds and mammals are killed by rapid constriction, which causes suffocation.

Predation and Defense Predators of Pantherophis gloydi include egrets, herons, hawks, raccoons, mink, and foxes. Young Eastern Foxsnakes are presumably eaten by large fish, frogs, turtles, shrews, weasels, and rodents (Harding 1997; Lee 2000b). Lee (2000b, 2) stated that “when disturbed, young fox snakes [Eastern Foxsnakes] may strike and bite, but older snakes rarely bite, even when handled; instead they shake or ‘rattle’ their tail vigorously and may spray a musky-smelling anal secretion (which is supposedly foxlike and hence its name).” Interaction with Humans Eastern Foxsnakes are often mistaken for a venomous species, such as the Eastern Massasauga (a native Michigan species) and the Copperhead (a snake that does not occur in the state), and many are needlessly killed for this reason. Ruthven et al. realized the benefit this species is to Michigan farmers and quoted R. L. Ditmars, who stated that “the good this species does in destroying the smaller injurious creatures of the fields, should cause it to be the recognized friend of the farmer. One snake is worth a dozen traps, for the reptile prowls into the burrows and nests of rats and mice and eats the entire brood” (1928, 96 [Ditmars 1907, 297–98]). Behavioral Characteristics For the behavioral characteristics of Pantherophis gloydi, see the sections “Habitat and Habits” and “Predation and Defense” in this account. Population Health Eastern Foxsnake populations have dramatically declined in many areas where they were once abundant. The primary threats to this species are considered to be loss of habitat and degradation of coastal marshes, human persecution, and illegal collecting for the pet trade (Evers 1994; Harding 1997). Actually, the four known populations in Michigan live in sites that are partially owned and protected by the state and federal government, but there is still relatively unrestricted use of these locations by the public. The Eastern Foxsnake is listed as Threatened by the MDNR and is protected by the state of Michigan. It is unlawful to take this species from the wild unless authorized under a permit from the director of the MDNR.

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Some specific suggestions for measures that would directly help the survival of this species have been made. Weatherby (1986) suggested that the dikes used by these species be mowed only between mid-June and midOctober. He also suggested that woody debris, such as hollow logs, be transported to areas where the snakes live to serve as nesting sites and shelter for hatchlings and young snakes. Still another suggestion is that prescribed burning be conducted before these snakes emerge from hibernation or on cold overcast days when Eastern Foxsnakes would likely be underground. Evers (1994) suggested that public education is needed to enable more people to identify Eastern Foxsnakes, to show the value of this species in rodent control, and to discourage illegal persecution and harassment of this snake. General Remarks Additional studies on the life history of both the Eastern Foxsnake and Western Foxsnake are drastically needed. The information gained could enhance our ability to protect and manage this species and shed light on the relationship between the Eastern Foxsnake and the Western Foxsnake.

Pantherophis vulpinus (Baird and Girard 1853) Western Foxsnake (represented by dots in the Upper Peninsula only) Identification See the preceding Eastern Foxsnake account. General Distribution See the preceding Eastern Foxsnake account. Michigan Distribution In Michigan, the Western Foxsnake occurs only in the central and western part of the Upper Peninsula. It is absent from Luce, Mackinac, and Chippewa counties in the eastern UP. It has only been recorded from Big Summer Island and possibly the Manitou Islands in Lake Michigan. Geographic Variation As far as I am aware, there are no distinct populations of this species in Michigan.

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FIG. 89. Western Foxsnake (Pantherophis vulpinus) from Delta County, Michigan. Photograph by James H. Harding.

Habitat and Habits The Western Foxsnake inhabits mixed forests, grasslands, scrubby oak and brush areas, hedge rows, pastures, and in some areas even road rights-of-way. These snakes are active mainly from middle or late April to October. A 1,010 mm (39.8 in.) male was once seen crawling across ice in February in Illinois when the temperature was 9.4ºC (48.9ºF) (Brown and Brown 1995). Western Foxsnakes hibernate in rock crevices, mammal burrows, and the foundations of various types of buildings. They often hibernate together. In Illinois, P. W. Smith (1961) found an aggregation of 16. In Wisconsin, Vogt (1981) found 166 in an old well (68 of them were hibernating underwater). Murphy (1997) reported Western Foxsnakes hibernating underwater under ice. Kile Kucher (pers. comm., 2009) detected Eastern Foxsnakes hibernating under more than .5 m (19 in.) of water in Shiawassee County. Western Foxsnakes are generally active in the daytime in the Upper Peninsula of Michigan. James H. Harding has seen live ones on the road during the day in the western part of the UP. A Western Foxsnake that lived near the house of Dr. Dean Premo (near the Paint River in the western part of the UP) was seen during the day for several years. In north-central Illinois, this snake can exist in very cultivated areas. They may even be found in fair numbers on road rights-of-way where corn and soybeans are planted right up to the border. Thirteenlined ground squirrels are abundant on road shoulders, and people who live in these areas have observed Western

2. Species Accounts

Foxsnakes entering and leaving the burrows of these mammals. Dr. Dale Birkenholz recorded these snakes occupying the burrows of thirteen-lined ground squirrels in a cemetery in Normal, Illinois, and I saw a Western Foxsnake that occupied a barn in a highly cultivated area near Illinois State University at Normal in 1965. P. W. Smith (1961) found Illinois Western Foxsnakes in shrubs and trees up to a height of at least 2 m (6.56 ft.). Western Foxsnakes appear to be excellent swimmers. I saw a very large individual swim, without resting, across an oxbow lake on May 15 near the Illinois River and Havana in north-central Illinois. When it reached the opposite shore, the snake climbed into the branches of an overhanging tree, where it lay for several minutes before I accidentally disturbed it. It dove into the water with the dexterity of a Watersnake. Referring to the Western Foxsnakes of northwestern Indiana, Minton (2001, 306–7) stated that “it persists longer than most large snakes in zones of intensive agriculture and remains moderately plentiful throughout most of its Indiana range. It finds refuge in pastures, around old buildings, and along railroad rightsof-way. It is often found near grain elevators. These snakes are terrestrial and secretive, apparently spending much time in the burrows and runways of small rodents.” Reproduction and Growth Most recorded observations of mating in Western Foxsnakes cluster in June (Ernst and Ernst 2003). Harding (1997, 315) reported that “male Western Fox Snakes will engage in ritualized combat, similar to that described for the Black Rat Snake. During these ‘wrestling matches,’ each combatant attempts to ‘top’ and ‘pin’ his rival by twining around him and pushing down on his head and body. The winners of these bouts appear to maintain a temporary dominance over the losers, and to have better success at mating with nearby females.” Gillingham (1974) described courtship and mating in the Western Foxsnake. His account is paraphrased and condensed in this paragraph. When the male finds a female, he probes her with his tongue. She usually moves away, and the male usually gives chase. If she is receptive, she stops. The male moves next to her, again probes her with his tongue, nudges her near the center of her body, and makes forward, jerking motions with his body. The female reacts by making similar motions, and he pushes his head onto her back, moving forward from his original

position. Progressing forward to her mid-body area, he pulls the back portion of his body into several S-shaped curves that contact the female, who then lifts these curves onto her back until he mounts her. Finally, after more jerking motions by the female, he puts his head behind hers. Insertion of one of the hemipenes of the male then follows, with the male holding the female by the neck during the remainder of copulation, which may continue for up to forty minutes. One case of mating in Western Foxsnakes gone wrong was reported by C. H. Pope (1944, 177–78), as follows: “Two fox snakes were once seen near Chicago in a curious position, one having swallowed the other’s head and neck. Since their bodies were undulating synchronously, and the one did not continue to engulf the other, their behavior must have been of a sexual nature; probably the male had bitten the female in courtship and carried his normal biting technique a little too far.” Oviposition usually occurs in July, and the nest sites may be rotten logs, stumps, sawdust piles, or even loose soil. Clutches contain from seven to twenty-nine eggs (Wright and Wright 1957). The eggs are white, have leathery shells, and cling together (Seigel and Fitch 1984). The twenty-nine eggs averaged 46.2 mm (1.82 in.) in length. Most eggs hatch in August, but hatching may occur as late as October. The hatchlings, unlike the adults, have dark markings on the top of their heads. The total body length of twenty-three hatchling specimens averaged 294 mm (11.57 in.). P. W. Smith (1961) reported clutches of eight to twenty-seven eggs for female Western Foxsnakes in Illinois; the eggs were buried in soil or under objects lying on the ground. Minton (2001, 307) reported that “a female from Jasper County, Indiana, laid 13 eggs on July 12. Ten hatched August 16 and 17. Road-killed snakes containing clutches of 14 and 8 eggs nearly ready to be deposited were found in northern Indiana on June 28 and July 13 respectively.” Diet Ernst and Ernst (2003) prepared a long list of the foods of the Western Foxsnake. Potential food items that would be available to this snake in the Upper Peninsula of Michigan are young cottontail rabbits, chipmunks, ground squirrels, mice, voles, rats, birds, and bird eggs. Juvenile Foxsnakes may find frogs, skinks, and earthworms to be food items as well.

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Predation and Defense Referring to predation of the Western Foxsnake in the Great Lakes region, Harding (1997, 315) stated that “the natural enemies of adult Western Fox Snakes undoubtedly include the larger birds of prey and predatory mammals, while their eggs and young would be vulnerable to snake-eating snakes, shrews, weasels, and many other small predators.” In my experience, most Western Foxsnakes when encountered try to escape by crawling away to cover. Some I have observed stand their ground, coil, raise their heads, and vibrate their tail. Sometimes, but not always, they have made rather short, “half-hearted” strikes. I have picked up Western Foxsnakes in the field only in north-central Illinois, but I assume they would act the same way in Michigan. When I actually picked up Foxsnakes (I never grabbed them), I was not bitten, and no musky secretions were ever sprayed on me, although a few large snakes coiled tightly around my arm, a rather uncomfortable experience. I am guessing that if a predator the size of a skunk or even a weasel grabbed a large Western Foxsnake, quite a struggle might ensue. Interaction with Humans Western Foxsnakes are often called pine snakes in Michigan. Their tendency to vibrate the tail when threatened sometimes causes them to be confused with rattlesnakes; however, no rattlesnakes inhabit the Upper Peninsula. Behavioral Characteristics For the behavioral characteristics of Pantherophis vulpinus, see the sections “Habitat and Habits,” “Reproduction and Growth,” and “Predation and Defense” in this account. Population Health The Western Foxsnake is not protected in Michigan, and if the Upper Peninsula continues to remain the same as it is today, I would venture to guess that this species will continue to be moderately abundant. General Remarks Pantherophis vulpinus (and its sister species P. gloydi) are the most generalized species of Ratsnakes in North America. The ancestral form of these two species, Pantherophis kansensis, is known from the Middle Miocene

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(Early Barstovian Land Mammal Age), 16 to 14.5 Ma BP (Holman 2000). The last appearance of Pantherophis kansensis was in the Late Miocene (Middle Hemphillian Land Mammal Age), about 9 Ma BP. The earliest appearance of the Pantherophis vulpinus–P. gloydi complex was in the Late Miocene (Late Hemphillian Land Mammal Age), about 5.5+ Ma BP. Thus the evolution from P. kansensis to the P. vulpinus–P. gloydi complex took place between Middle and Late Hemphillian times.

Regina septemvittata (Say 1825) Queen Snake Identification This small aquatic species has a relatively small head and a background color of brown, olive, or gray. A light yellowish stripe on each side on the second and bottom half of the two lowest rows of scales is a distinguishing field mark of the Queen Snake. These stripes continue onto the scales of the upper and lower lips. Some lesser, darker stripes sometimes occur on the dorsum in young and some adult Queen Snakes. However, all these stripes may fade on old Queen Snakes, which may become almost uniform in color. Both the chin and throat are yellow. The belly is a faded yellow color and marked with four brown fore and aft stripes that may merge or fade toward the tail. The scales are heavily keeled, and the anal plate is divided. The total length of adults ranges from 340 to 922 mm (13.4–36.3 in.) (Harding 1997). Most of the adult Regina septemvittata that I have seen are about 600 mm (23.6 in.) in length. General Distribution The general range of this snake is from southeastern Pennsylvania, western New York, and southwestern Ontario, west to southeastern Wisconsin and adjacent northeastern Illinois, and south to northern Georgia, Alabama, and eastern Mississippi. Isolated populations are found in the extreme southwestern corner of Mississippi, in the Ozarks of northern Arkansas, and in southern Missouri (Ernst and Ernst 2003). Michigan Distribution The Queen Snake is not known in the Upper Peninsula, but there is a record from Bois Blanc Island near the

2. Species Accounts

Straits of Mackinac. Records of this snake in the Lower Peninsula are scattered, with only two important clusters of county records. In western Michigan, the records include a string of locations from Cass County in the southwestern part of the first tier of counties to Grand Traverse County in the northwestern part of the state (see Douglass 1977). In southeastern Michigan, they occur in Ingham, Washtenaw, Monroe, Wayne, Oakland, Genesee, and St. Clair counties. An isolated record of this species was made in Ogemaw County in the southeastern part of the upper half of the Lower Peninsula (see Allen 2003). This odd distribution of records may reflect the fact that this is a specialized species with narrow habitat and dietary requirements under stress from human-caused changes in its habitat.

hypothetically stress the snakes and lead to reduced immune function and disease. I am not aware of any data on the spring emergence and fall hibernation dates of the Queen Snake in Michigan, but in Wisconsin Vogt (1981) reported that this snake can be seen from May to September. Wood (1949) reported that in southeastern Ohio, this species hibernates communally. Ernst and Ernst (2003) found this species hibernating in muskrat and crayfish burrows, and Vogt (1981) postulated that Queen Snakes in Wisconsin hibernate under rocks or in or near streams that are spring fed.

Geographic Variation As far as I am aware, no distinct populations of Regina septemvittata occur in Michigan, and no subspecies are presently recognized. Three other species of the genus Regina are recognized: R. alleni (Garman 1874), the Striped Crayfish Snake; R. grahamii Baird and Girard 1853, Graham’s Crayfish Snake; and R. ridgida (Say 1825), the Glossy Crayfish Snake (Crother 2008). Habitat and Habits The Queen Snake is most often found in the clean waters of brooks, streams, and small rivers in Michigan. Ruthven et al. (1928) indicated that it was found hanging over streams from projecting willows in habitats that it frequented near Ann Arbor. Crayfish must be present for these snakes to feed on in these habitats. In a physiological test of the permeability of reptile skin, it was found that the Queen Snake had the most permeable skin of any snake studied (Stokes and Dunson 1982). This high permeability indicates this snake must live in or near water and will likely have health problems in polluted or chemically treated aquatic situations. I once caught several Queen Snakes in 1946 in Brandywine Creek near Indianapolis. The creek was very muddy and ran through an open pasture; all of the snakes had swollen lesions on their bodies. My guess is that the area had recently been converted to pasture. Somewhat later, my mentor at the time, S. A. Minton, agreed with me about the probable new conversion of the land to pasture. This could

Fig. 90. Queen Snake (Regina septemvittata). Photograph by James H. Harding.

During their active period of the year, Queen Snakes tend to forage in the morning, usually followed by a period of basking. Basking sites may be overhanging tree branches or open areas along the stream bank (at least that is what I have observed in northern Alabama and central Indiana). Some authors have suggested that Queen Snakes are active at night (e.g., Mount 1975). But, relative to Indiana, Minton (2001) stated that Queen Snakes are not active at night. Regina septemvittata have small home ranges. C. H. Ernst observed that most of the activity in a group of 205 Queen Snakes in southeastern Pennsylvania was associated with a stone dam that was used as a retreat in both summer and winter. The farthest any of these snakes moved away from this dam was 55 m (59.95 yd.), and that was one male. Of seventy-five recaptures, 80 percent of the snakes were within 25 m

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The Amphibians and Reptiles of Michigan

(27.25 yd.) of the dam (Ernst and Ernst 2003). Newcomer et al. (1974) suggested that Queen Snakes have the ability to use the sun to orient to a specific shoreline. Reproduction and Growth Minton (2001, 277) stated that the “mating [of the Queen Snake] was observed May 28 in central Indiana, but presence of well-developed embryos in a snake taken May 25 may indicate fall or early spring mating as well.” An abbreviated account of courtship and mating in Regina septemvittata by Ford (1982a) is presented as follows: 1. The male finds the female and examines her with his tongue. 2. The male mounts the female, crawls forward to align their bodies, and bounces on her by moving the front part of his neck. 3. Following the bouncing behavior, which takes place at high and low speeds, the male attempts to insert one of his hemipenes. 4. When intromission is complete, the male performs caudocephalic waves. Most Queen Snakes are born from mid-August to mid-September. Fifty-three hatchlings from southeastern Pennsylvania had mean total body lengths of 205 mm (8.1 in.). Relative to growth rate in this species, Wood and Duellman (1950) reported that in Ohio a 50 percent increase in total body length occurred during the second year, and that growth rates diminished thereafter. Diet Crayfish in the soft-shelled (post-molting) stage are the diet staple of Regina septemvittata. Other animals are occasionally eaten (see list in Ernst and Ernst 2003, 297) but form a rather incidental part of the diet. In 44 stomachs of New York Queen Snakes examined by Raney and Roecker (1947), crayfish made up 99.2 percent of the food eaten. In 110 stomachs of Kentucky R. septemvittata examined by Branson and Baker (1974), 98.6 percent of the volume of food eaten consisted of crayfish. Ernst and Ernst (2003) made observations on the feeding behavior of Queen Snakes in a small Pennsylvania stream. The snakes foraged among rocks in the stream, and from time to time they ran crayfish out of their hiding places. These displaced crayfish were small and appeared to have just molted. The snakes

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grabbed the crayfish from behind and swallowed them tail first. Predation and Defense Ernst and Ernst (2003) provided a detailed list of recorded predators of Queen Snakes. Following is a shortened list of these animals that would be potential predators of R. septemvittata in Michigan: great blue herons, crayfish (of juvenile snakes), Blue Racers, watersnakes, raccoons, otters, and mice. Defensive behavior by Queen Snakes mainly consists of diving into the water and swimming away to hide under rocks and logs or in crayfish burrows. Queen Snakes rarely bite (I have never been bitten by one), but they are able to squirm vigorously when grabbed and usually expel feces and musk from their vents. Interaction with Humans In Michigan, I have talked with several people who have mistaken Queen Snakes for Gartersnakes, and Minton (2001) stated that in Indiana, they are usually considered to be some type of Gartersnake. Ernst and Ernst (2003, 298) stated that “unfortunately, water pollution and acid rain have combined to reduce crayfish populations in many parts of its eastern range, and this, along with habitat drainage, has consequently eliminated R. septemvittata from many areas where it was common.” They also reported that at one site in southeastern Pennsylvania, teenage boys shot about one hundred basking Queen Snakes. Harding (1997) reported that Queen Snakes are often killed by fishermen who think the snakes eat game fish. Behavioral Characteristics For the behavioral characteristics of Queen Snakes, see the sections “Habitat and Habits,” “Reproduction and Growth,” “Diet,” and “Predation and Defense” in this account. Population Health This is a rare and declining species in Michigan. The highly permeable skin and the specialized diet of soft-shelled crayfish obviously make Queen Snakes vulnerable to water impurities and crayfish population problems. The Queen Snake is considered a Species of Special Concern by the MNFI biologists; it is listed as

2. Species Accounts

Endangered in Wisconsin and a Special Concern species in Arkansas. General Remarks This very specialized and vulnerable snake needs baseline biological and distributional research in Michigan.

Storeria dekayi (Holbrook 1836) DeKay’s Brownsnake (composite range of two intergrading subspecies) Identification DeKay’s Brownsnake is a diminutive species with a background color of grayish brown or tan and two parallel rows of dark spots running down the back. Sometimes the spots are connected by dark crossbars that create a ladder-like pattern. The area between the rows of dark spots tends to be a lighter shade than the spots themselves, and this produces the effect of the snake having a single wide stripe down the middle of the back. The head is small and dark on top. The belly varies in color from cream to pink and may be marked with small dots along the edges. The scales are keeled, and the anal plate is divided. Harding (1997) reported that in the Great Lakes region the total length of adults ranges from 230 to 527 mm (9.1–20.7 in.), but that very few Brownsnakes are longer than 380 mm (15.0 in.).

Fig. 91. DeKay’s Brownsnake (Storeria dekayi) from Ingham County, Michigan. Photograph by James H. Harding.

Two subspecies of Brownsnakes mix together in Michigan in an odd way (see the “Geographic Variation” section in this account). These subspecies are the Northern Brownsnake, Storeria dekayi dekayi (Holbrook 1836), and the Midland Brownsnake, Storeria dekayi wrightorum Trapido 1944. These two subspecies differ in appearance: the Northern Brownsnake typically has few or no crossbars linking the spots on the back, and the Midland Brownsnake has many crossbars linking the spots on the back. General Distribution Storeria dekayi occurs from Quebec and Ontario, Canada, and southern Maine south to Florida and the Gulf Coast, west to Minnesota, eastern Nebraska, Kansas, Oklahoma, and Eastern Texas, and south into Mexico and Honduras. The first snake I ever saw outdoors was a DeKay’s Brownsnake coming out of a crack in the sidewalk while I was on my way to school in Indianapolis. Oddly, on my first trip out of the United States, the first snake I saw was a DeKay’s Brownsnake on a road in Mexico. Michigan Distribution Storeria dekayi occurs in at least four counties in the Upper Peninsula of Michigan: Schoolcraft and Delta counties in the eastern part, and Baraga and Keweenaw counties in the western part. This species has been reported from North Manitou, South Fox, and South Manitou Islands in the Lake Michigan Archipelago. In the Lower Peninsula, this species is very widespread, with records lacking in only a few counties, probably because of a lack of surveys taken in those areas. Oddly, this species has been collected from more counties in the upper half of the Lower Peninsula than in the bottom half, even though it has always been my impression that this species becomes less common farther north. Geographic Variation The Northern Brownsnake subspecies (S. d. dekayi) intergrades with the Midland Brownsnake subspecies (S. d. wrightorum) throughout the Lower Peninsula, with the Midland Brownsnake also occurring in pure form in the Upper Peninsula (see Conant and Collins 1998, 308, map). It is very difficult to identify either subspecies of Brownsnake with certainty in Michigan, either in the Upper or Lower Peninsula. Minton (2001) reported that

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The Amphibians and Reptiles of Michigan

many Indiana Brownsnakes are not characteristic of the subspecies of S. d. wrightorum. Obviously more work needs to be done on variation in Brownsnakes in the Midwest. Two other subspecies of Brownsnakes are also recognized in the United States: the Marsh Brownsnake, S. d limnetes Anderson 1961, and the Texas Brownsnake, S. d. texana Trapido 1944. Habitat and Habits The DeKay’s Brownsnake is ubiquitous in its choice of habitats, occurring in nearly all types of terrestrial and nonsaline wetland habitats that are present within its range. This little snake often occurs in dense populations and is common in both urban and suburban areas, as long as there are objects to hide under and earthworms or slugs available to eat. Storeria dekayi is a hearty species that becomes active during the first serious spring thaw and remains active until October and even into November in most of its range in Michigan. In Kansas, Fitch (1999) made 62 percent of his recaptures of this species from March through June. In Michigan, I see more on the road in late September than at any other times, and I presume they are moving to hibernating areas. C. H. Ernst reported that when the weather becomes severely cold, Brownsnakes must find hibernating sites below the frost line. These sites include ant hills, stone walls, derelict wells, rodent burrows, sawdust piles, and compost heaps. He also stated that some individuals return to the same site year after year (Ernst and Ernst 2003). Carpenter (1953) found two Brownsnakes in an anthill hibernaculum in Washtenaw County, Michigan, on February 25, 1951, at a depth of eight to nine inches below the surface. One of these two snakes had been seen emerging from the site on April 3 the previous year. Other snakes recovered from the ant hill hibernaculum on February 25 were twenty-one Eastern Gartersnakes, eleven Northern Ribbonsnakes, fifteen Butler’s Gartersnakes, four Common Watersnakes (two were dead), one Smooth Greensnake, and one Northern Red-bellied Snake. The snakes were at a wide variety of depths in the anthill hibernaculum. I have repeatedly seen Brownsnakes, Northern Redbellied Snakes, Northern Ribbonsnakes, and Eastern Gartersnakes in middle and late September, all moving in the same direction across a limited stretch of road in the northwestern part of the Lower Peninsula. I am

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speculating that they were heading toward the vicinity of their hibernating site. Minton (2001, 283) stated that “I marked 45 [Brownsnakes] at a hibernating site less than a hundred yards from Wishard Hospital in urban Indianapolis. They hibernated at the base of a bridge abutment along with young and half grown Eastern Garter Snakes. Recaptures of 18 marked snakes indicated only one animal moved more than about 50 yards from the den.” Other reports in the literature indicate that the home ranges of most Brownsnakes are small, but that some individuals may travel relatively long distances. Freedman and Catling (1979) reported that in Ontario, Canada, a male 310 mm (12.2 in.) in length moved 374 m (407.7 yd.) within thirty days. Reproduction and Growth Female DeKay’s Brownsnakes give birth to their young (are viviparous) rather than laying eggs, and the snakes become sexually mature at a minimum snout-to-vent length of 170 to 175 mm (6.7–6.9 in.) (Kofron 1979; Mitchell 1994). Mating may occur as early as February or March in New York on Long Island (Clausen 1936) and probably as late as August in Canada (Trapido 1940). Female Brownsnakes are able to store sperm during the winter for fertilization in the spring (Fox 1956). To learn something about the contribution that scent or pheromones make in helping male DeKay’s Brownsnakes find females, C. H. Ernst rubbed the cloaca of a Pennsylvania female Brownsnake on a linoleum floor in a complicated, twisting pattern. Three males were released one at a time at the start of the trail. Each male extended its tongue rapidly, twitched its tail, and then rapidly and precisely followed the invisible trail through all its twists and turns (Ernst and Ernst 2003). Noble (1937) published a detailed report on the courtship and mating of DeKay’s Brownsnake. All of the matings he observed occurred in the morning. Noble’s account of this behavior is condensed and paraphrased here. The male identifies the female by examining her vent and tongue-flicking. He then rubs his chin along her back while moving forward. The female usually crawls away at this point, the male following after her. He next aligns his body parallel to hers, moving his chin along her back until he reaches her head. He then tries to wrap the back part of his body around that of the female.

2. Species Accounts

The vents of the two animals are juxtaposed as the male initiates caudocephalic waves that move forward along his body, as he tries to keep his chin in a position above the female’s neck. The male then lifts the vent region of the female upward into proper position for the insertion of one of his hemipenes. At this point, the female may again move away, dragging the male along with her. During copulation, the male makes forward thrusts with his tail. These consist of two or three rapid thrusts interrupted by short pauses. DeKay’s Brownsnakes give birth to their young between June and September. Most of the young appear in July and August, and the average number of newborns are about thirteen (Ernst and Ernst 2003). The young are dark brown or black with a light-colored neck ring (occipital collar). The newborns are tiny, with a mean snout-to-vent length of just 97 mm (3.8 in.). In 1970 I kept a female Brownsnake from Ingham County, Michigan, over the summer in a terrarium. The snake was 285.5 mm (11.2 in.) long, and I released her in late August where I originally found her. In early August she had unexpectedly given birth to eleven young, seven of which were dead, wrapped in their fetal membranes. The four live young were released forthwith. Minton (1972, 240) reported that “the smallest size group of snakes observed at [an] Indianapolis den in the fall consisted of individuals 140 to 225 mm. long and seemed to represent early and late broods of the previous summer. A year after their first hibernation these snakes measured 280 to 305 mm. and were very probably sexually mature.” He also reported that a male Storeria dekayi 205 mm (8.1 in.) long that was captured October 9, 1948, grew to 290 mm (11.4 in.) by March 28, 1950, and reached 320 mm (12.6 in.) by September 9 of the same year. Diet Earthworms and slugs are by far the most common prey recorded for DeKay’s Brownsnake, although other small animals such as snails, insects, isopods, mites, spiders, small amphibians, and amphibian eggs have been recorded (see Ernst and Ernst 2003, 332). Rossman and Myer (1990) described the procedure Brownsnakes employ to feed on snails. The snake seizes the soft body of a snail using specialized elongated maxillary teeth and pushes the animal along the substrate until it can wedge it against a stable object. Then it applies torsion

to extract the soft body from the shell and swallows only this soft part. Predation and Defense This small snake falls prey to numerous predators. Some of the predators that have been reported to attack DeKay’s Brownsnakes include shrews, opossums, raccoons, domestic cats, skunks, weasels, and snake-eating snakes. Ernst and Ernst (2003, 332) provide a detailed list of these predatory species. Brownsnakes almost never bite in defense (I have never been bitten by this species), but they do twist about and spray musk on their captors. Two authors have reported death-feigning in this snake. When E. A. Liner (1977) touched a DeKay’s Brownsnake, it writhed and rolled over on its back and appeared to be dead and dried up. When F. E. Hayes (1987) caught a Brownsnake, it became flaccid and unresponsive, even when it was turned over on its back. Hayes caught others that hid their head under coils of their body. Interaction with Humans As they do for other small, inoffensive snakes, people in Michigan tend to leave DeKay’s Brownsnakes alone. I have had people tell me they are “baby garden snakes.” I think they meant “baby garter snakes,” and I imagine the stripe on the back of some of the snakes has lead to this misnomer. Behavioral Characteristics For the behavioral characteristics of Storeria dekayi, see the sections “Habitat and Habits,” “Reproduction and Growth,” “Diet,” and “Predation and Defense” in this account. Population Health Storeria dekayi is not protected in Michigan and is locally abundant in the state. These snakes are adversely affected by agricultural development, but in those urban and suburban areas where toxic elements are under control, and as long as people living in these areas leave flat pieces of trash, boards, or tile shards around places where earthworms, slugs, and snails abound, these little snakes should be all right. But, as Harding (1997, 295) stated, “Brown Snake colonies in urban and agricultural settings are in constant danger of rapid extirpation by development activities or exposure to toxic chemicals.”

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General Remarks Much more can be learned about this interesting snake species, as it still exists in relatively large colonies here and there in Michigan. The frequency of death-feigning would be especially interesting to know more about.

Storeria occipitomaculata occipitomaculata (Storer 1839) Northern Red-bellied Snake Identification The Northern Red-bellied Snake is a very small species with a background color that can range from black, brown, or reddish brown to gray. Different populations can be a single color or have brown or gray phases, for example, that are equally common. The head is small and the neck is narrow. The upper part of the body may be unmarked, or it may have from two to four thin, dark stripes that extend down the back and sometimes the sides. An obscure light stripe may also run down the middle of the back. The top of the head is usually dark brown but can be reddish brown; the chin and throat are pale. Often, a light spot occurs behind and below each eye. Three light spots mark the neck, one on the top and one on each side. These neck spots may fuse to form a partial ring around the neck, and sometimes these snakes are misidentified as “Ring-necked Snakes.” The belly is usually bright red but sometimes can be pinkish red or orange, or less frequently even light yellow. The scales are keeled, and the anal plate is divided. The sexes are difficult to determine based on external features. The total length of this species ranges from 203 to 406 mm (8–16 in.) (Harding 1997). General Distribution The Northern Red-bellied Snake ranges from Nova Scotia west to southern Saskatchewan, Canada, and south to the Carolinas, northern Georgia, northeastern Alabama, Tennessee, central Arkansas, and eastern Oklahoma (Ernst and Ernst 2003). Michigan Distribution The Northern Red-bellied Snake occurs in all of the counties of the Upper Peninsula and on Isle Royale and Drummond Islands. It also occurs on Beaver, Garden,

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High, Squaw, and Whiskey Islands in the Lake Michigan Archipelago. It is widespread in the upper half of the Lower Peninsula except that it has not been recorded from Manistee, Benzie, and Leelanau counties bordering Lake Michigan. It is recorded only in Allegan County in the southwestern part of the Lower Peninsula but is moderately common in the southeastern part. Oddly, it is recorded in only two counties, Washtenaw and Wayne, from the bottom two tiers of counties in the state. Geographic Variation Only one subspecies of this snake, Storeria occipitomaculata occipitomaculata, occurs in Michigan. This subspecies in Michigan and elsewhere may have individuals that are of either the brown or gray color phase (see the earlier section “Identification”), but the genetic studies of Grudzien and Owens (1991) show no evidence of separate lineages in the two color phases. Two other subspecies exist outside of Michigan: S. o. obscura Trapido 1944, the Florida Red-bellied Snake, and S. o. pahasapae Smith 1963, the Black Hills Red-bellied Snake. Habitat and Habits In Michigan, Northern Red-bellied Snakes may be found in moist woodlands—both pine and mixed—as well as meadows and abandoned farmland. It can often be found under rotting logs, boards, and debris in old dumps and trash piles (Holman et al. 2006; Ernst and Ernst 2003). In Michigan, this snake is usually active from May to late September. Migration to its hibernacula usually begins sometime in September, and usually about the middle of the month in the Lower Peninsula, from my own observations. Vogt (1981) found the migration of this subspecies to hibernating sites in Wisconsin also began in September. Data from Wisconsin also show that hibernation sites are below the frost line in such places as soil, gravel, rock crevices, ant mounds, mammal burrows, rotting logs, and loose bark. In an ant mound hibernaculum in Washtenaw County, Michigan, Carpenter (1953) found two Northern Red-bellied Snakes hibernating fourteen to fifteen inches below the surface on February 25, 1951. (Other snakes that were also occupying this hibernaculum are listed in the section “Habitat and Habits” in the DeKay’s Brownsnake account.) Ernst and Ernst (2003) found these snakes were active during the late morning or afternoon in the

2. Species Accounts

Fig. 92. Northern Red-bellied Snake (Storeria occipitomaculata occipitomaculata) from Ingham County, Michigan. Photograph by James H. Harding.

spring or fall, but during the summer they were active mainly between 10 a.m. and noon. Northern Red-bellied Snakes are able to cover a good bit of distance in a relatively short time for such a small snake. Blanchard (1937) recaptured a northern Michigan female that had moved about 400 m (436 yd.) in twenty-four hours. Another specimen was recaptured after seven days only 30 m (32.7 yd.) from the place where it was first taken. In Illinois, P. W. Smith (1961) found Red-bellied Snakes climbing in vegetation above the ground on two occasions. Reproduction and Growth F. N. Blanchard (1937) studied S. occiptomaculata in northern Michigan, and R. D. Semlitsch and G. B. Moran (1984) studied this species in South Carolina. It appears that both male and female S. occiptomaculata become sexually mature at the end of the first year of their growth, but they probably do not mate until the next spring or summer when they are two years of age. The sperm of Northern Red-bellied Snakes may remain active for at least four months and can be stored over the winter in the reproductive tracts of either the males or females (Fox 1956). Mating may occur as early as May and as late as September (Ernst and Ernst 2003). In 1995, J. P. S. do Amaral studied the thermal ecology of the Red-bellied Snake in northern Michigan and found that gravid (pregnant) females consistently

maintained higher body temperatures than males or nongravid females. Like DeKay’s Brownsnake, Red-bellied Snakes give birth to their young. The young snakes appear one at a time within a membrane that ruptures soon after birth (Nelson 1969). In northern Michigan, only one litter is born per year (Blanchard 1937). Litters in the northern part of the range of this species are usually composed of fewer individuals, averaging seven in the north and nine in the south (Ernst and Ernst 2003). The newborn Red-bellied Snakes in general resemble the adults in markings and color. They may resemble the young of the DeKay’s Brownsnake, except for the brighter belly color. The neonates are tiny and have a mean total length of 82 mm (3.2 in.) (Brodie and Dulcey 1989). In Indiana, they range from 77 to 90 mm (3.0–3.5 in.) in total length (Minton 2001). South Carolina newborns grew to 61 to 90 mm (2.4–3.5 in.) in snout-to-vent length by their first winter and reached 110 mm (4.3 in.) by the next summer (Semlitsch and Moran 1984). In northern Michigan, Northern Red-bellied Snakes reached a total length of 170 to 210 mm (6.7–8.3 in.) within a year (Blanchard 1937). Diet The feeding habits of Northern Red-bellied Snakes are generally similar to those of Brownsnakes, earthworms and slugs being the preferred food of both. Brownsnakes,

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The Amphibians and Reptiles of Michigan

though, consume a wider variety of prey (Rossman and Myer 1990). Red-bellied Snakes have the same elongated maxillary teeth as Brownsnakes that function to deeply penetrate and hold soft-bodied prey (see Rossman and Myer 1990, 436, fig. 2) as well as the same behavioral mechanisms to extract the soft bodies of snails from their shells (see “Diet” in the DeKay’s Brownsnake account), and have been observed engaging in this activity in the laboratory (Rossman and Myer 1990). Predation and Defense A detailed list of the recorded predators of Northern Red-bellied Snakes is provided in Snakes of the United States and Canada (Ernst and Ernst 2003, 337). Animals in Michigan that are potential predators of this species are largemouth bass, Blue Racers, chickens, crows, kestrels, hawks, ground squirrels, and chipmunks. When threatened, a Red-bellied Snake will flatten its head and body and release fecal matter and musk. When they are handled, they elevate their upper lips to expose the elongated maxillary teeth in a rather hideous-looking grin. They may also push the side of their head against their antagonist so these teeth snag the skin (do Amaral 1999; Ernst and Ernst 2003). However, they almost never actually bite, even when handled. Other odd defensive behaviors have been reported for this species. R. Jordon Jr. (1970) reported that Red-bellied Snakes may go into convulsions, roll over on their backs, gape, and become contorted and motionless. Vogt (1981) reported that individuals of this species would extend their body straight out and become rigid when exposed to predator stress. Interaction with Humans Northern Red-bellied Snakes are generally called “red-bellied snakes” or “red-bellied garter (or ‘garden’) snakes” in Michigan. I have talked to only a couple of Michiganians about Red-Bellied Snakes and am ashamed that I have not talked to more. Behavioral Characteristics For the behavioral characteristics of S. o. occipitomaculata, see the sections “Habitat and Habits,” “Reproduction and Growth,” “Diet,” and “Predation and Defense” in this account.

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Population Health This snake is not specifically listed by the MDNR in Michigan. I have found that this species appears to be common in moist woodlands in Michigan, and I have seen many more of them in the state than its close relative, the Brownsnake. But the Red-bellied Snake may not be as abundant in suburban areas as the Brownsnake, and I have not found them in truly urban situations. I have found that they are especially active at two times during the year in both the northern and southern parts of the Lower Peninsula. Usually after the first cold spell in August, I find them crossing the roads in fair numbers. I also often find them at this time under objects that I think must be temporary shelters, some of these being mere pieces of paper littering a roadside. Then, beginning about the middle of September, I find them crossing the roads in much larger numbers, almost always heading in the same direction. Often they are accompanied by smaller numbers of Brownsnakes, but both species are heading in the same direction. I take this to be a migration toward hibernating sites. I think the primary activity for the protection of Red-bellied Snakes in Michigan should be the protection of their natural habitats in the moist woodlands, both broadleaf and mixed broadleaf and pine. General Remarks Ernst and Ernst (2003) reported that Red-bellied Snakes are considered to be uncommon or rare in most states. Given the fact that large populations still occur in Michigan, I would suggest that this would be a fine place for baseline studies to discover, for example, what this species eats in this state other than earthworms, slugs, and snails. Happily, modern studies of the dietary habits of snakes do not require the sacrifice of the animals, as in past decades.

2. Species Accounts

Thamnophis butleri (Cope 1889) Butler’s Gartersnake NOTE: Three species of Thamnophis, all having three prominent stripes, occur in Michigan. In some places in the state, it is possible to find all three species occurring in the same locality, and occasionally, all three may even be found under the same board or piece of sheet metal. All three species are attractive snakes. Identification Of the three Thamnophis species, Butler’s Gartersnake is probably the most difficult to identify. It is a rather small snake that has a shorter total body length, stouter physique, and relatively smaller head than the other two species of Thamnophis in Michigan. The background color may be black, brown, or olive brown. Some have two rows of black spots running down the back between the two side stripes. On the forward part of the body, the side stripes are on the third row of scales above the wide belly scales and encroach on the adjacent portions of scale rows two and four. The head is small, barely wider than the neck, and often bears two very small yellow spots at the back. If these spots are present, they are very good field marks. The scales of the lips are usually yellow and sometimes have some brown speckles on them. The scales are keeled, but the anal plate is single. The total length of adults is said to range from 380 to 737 mm (15–29 in.) (Harding 1997).

Geographic Variation No distinct populations of this species have been recognized in Michigan. No subspecies are recognized in Thamnophis butleri. Butler’s Gartersnake is closely related to two other species of Gartersnakes, though—the Shortheaded Gartersnake (Thamnophis brachystoma) to the east and the Plains Gartersnake (T. radix) to the west. Habitat and Habits Damp, open places, such as wet meadows and pastures; grassy areas near ponds, lakes, and streams; road rightsof-way near wet fields; and even city lots and grassy areas near golf courses are occupied by Butler’s Gartersnake in Michigan. It is one of those snakes that has, in some cases, benefited from urbanization (Minton 1968; Vogt 1981). From my own observations, the activity cycle of this snake appears to extend from early April until about October or early November in Michigan. Conant (1951) collected this species in every month except December and found there was a marked activity period in April and a lesser peak in October.

General Distribution Butler’s Gartersnake occurs from central Ohio and central Indiana north through eastern Michigan and the southern tip of Ontario, Canada. Isolated populations have been found in southeastern Wisconsin and southcentral Ontario.

Fig. 93. Butler’s Gartersnake (Thamnophis butleri) from Ingham County, Michigan. Photograph by James H. Harding.

Michigan Distribution This snake has not been recorded from the Upper Peninsula of Michigan. It was once found on the shore of Stony Island, Huron County, Michigan (Ruthven 1911). It occurs in roughly the southeastern half of the Lower Peninsula with two additional local occurrences in Presque Isle and Alpena counties in the northeastern part of the Lower Peninsula.

Carpenter (1952a) was unable to find Butler’s Gartersnakes in the woods in Michigan and thought that woodlands probably acted as a barrier to their dispersal. These snakes sometimes travel long distances to find food. Carpenter also reported that a Michigan adult traveled 121 m (131.9 yd.) in two hours. Minimum home ranges for three Butler’s Gartersnakes in Ontario were 50, 50, and 600 m2 (54.5, 54.5, and 654 sq. yd.)

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(Freedman and Catling 1979). These researchers also noticed that Thamnophis butleri had a tendency to avoid crossing roads. This is certainly a lucky adaptation for this species, which is well known for its awkward movements on land: Reddick (1895, 261) stated that “it is short and chubby, and its movement is very characteristic of it. It does not have the gliding movement of E. saurita [Eastern Ribbonsnake] nor the swift and active movement of the Natrix sipedon [Northern Watersnake], but seems rather to exert a large amount of force to do little crawling. The movement is so characteristic that I believe anyone having once seen the peculiar way in which it tries to hurry itself away would ever after be able to recognize it at a distance.” I have observed Butler’s Gartersnakes trying to crawl across blacktop roads in Michigan several times, and they literally wriggled in place when they were frightened. On the other hand, when they are crawling through grass and brambles, they seem as hard to catch as the other two species of Thamnophis in Michigan. In southeastern Michigan, Butler’s Gartersnakes hibernated for about 150 days and emerged from late in March to late in May. Meadow vole tunnels and ant mounds were used for hibernacula there (Carpenter 1953). An ant mound in Washtenaw County, Michigan, excavated on February 25, 1951, yielded fifteen living Butler’s Gartersnakes. They were found about fourteen to twenty-seven inches below the surface. Seven of the fifteen were found at a depth of about twenty inches. Reproduction and Growth Carpenter (1952b) found that the smallest gravid female he examined in Michigan had a snout-to-vent length of about 345 mm (13.6 in.), which was within the size range typically reached by females of this species in their second spring. He also found a male with a snout-to-vent length of 321 mm (12.6 in.) courting a larger female; this male was also within the size range reached by males of this species in their second spring. Breeding begins in March and April, right after hibernation. Ford (1982b) reported that males actively look for females by following their pheromone trails. Noble (1937) recorded courtship and mating activities of Butler’s Gartersnake, which is condensed and paraphrased here. The male tries to get on top of

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the female and rubs his chin on her back as he crawls forward until her neck is reached. He also touches her back with his tongue as he moves along. By the time his chin rests on her neck, loops of his body are across her back. Eventually, his cloacal region is bent to be forced under her body. His body and tail then produce rhythmic caudocephalic waves, and one of his hemipenes is usually inserted within a few minutes. The anterior part of the cloaca of mated females contains a plug that blocks the opening to the oviduct; the male apparently forms this obstruction after ejaculation (Devine 1977). This makes the female temporarily unavailable to other males and reduces the likelihood of multiple doses of sperm. Typically eight to ten young are born in August and early September. The length at birth has been measured at 125 to 185 mm (4.9–7.3 in.). Carpenter (1952b) found that in Michigan the annual growth period is 153 days (from May through September) and that as the snakes grow larger, their growth rate decreases. Diet At present in Michigan, Butler’s Gartersnakes feed principally on earthworms. Carpenter (1952a) found that of the Michigan food records he made, 83 percent were for earthworms and 10 percent for leeches. Catling and Freedman (1980) stated that 96 percent of the prey items of Butler’s Gartersnakes were earthworms, and they suggested that leeches were probably the principal part of the diet of T. butleri before the introduction of European earthworms. Relative to Catling and Freedman’s supposition about leeches having been a more important dietary item at an earlier time is an interesting mention from Ruthven et al. (1928, 119): “An additional observation on the food-habits [of T. butleri] was made in 1908, when several leeches were taken from the stomach of a specimen found under a stone on the shore of Stony Island, Huron County. . . . In nature the form [Butler’s Gartersnake] probably subsists on such weak food.” Even though worms are the top food of Butler’s Gartersnakes, these snakes are able to capture and eat many different types of prey. Catling and Freedman (1980) reported that Butler’s Gartersnakes had no trouble capturing and eating small fish that were put in their water bowl. Carpenter (1952a) reported that captive T. butleri ate small frogs, toads, and salamanders.

2. Species Accounts

Predation and Defense Not much has been written about predation on Butler’s Gartersnakes. Vogt (1981) thought that birds, Milksnakes, and carnivorous mammals, including domestic cats, probably eat them. Harding (1997, 277) stated that “this snake is surely preyed upon by most predators within its range; a list of known and likely enemies would include other snakes (such as Racers and Milk Snakes), various birds (e.g., crows, hawks, and owls), and mammals (including raccoons, skunks, weasels, shrews, foxes, and domestic cats and dogs).” When T. butleri is first approached by a possible predator, it tries to flee by throwing its body into frantic sideways motions. This motion may confuse predators that are accustomed to snakes moving rapidly forward when they crawl. When handled, Thamnophis butleri may spray musk on the captor, but they rarely attempt to bite. Interaction with Humans In Michigan most people recognize Gartersnakes (sometimes called “garden snakes”), but they do not seem to have separate names for the three species that occur in the state. Most people consider them harmless and tend to leave them alone, although others dogmatically kill any snakes they find on their property. Behavioral Characteristics For the behavioral characteristics of Butler’s Gartersnake, see the sections “Habitat and Habits,” “Reproduction and Growth,” and “Predation and Defense” in this account. Population Health This snake is relatively common in certain areas of the state. The rapid bulldozing that occurs in many urban and suburban areas has undoubtedly eliminated many once thriving colonies of Butler’s Gartersnake. General Remarks Newly born and juvenile Butler’s Gartersnakes are slender little animals, quite unlike the chubby adults.

Thamnophis sauritus septentrionalis Rossman 1963 Northern Ribbonsnake Identification The Northern Ribbonsnake is an alert, nervous, slender snake with a long tail that is a quarter to a third of the length of its body. The body has a background color of dark brown or black that is interrupted by three sharply contrasting yellow or white stripes. Unlike the Butler’s Gartersnake, the head of the Northern Ribbonsnake is distinctly wider than the neck. Immediately in front of the large eyes is a small, light-colored bar. The lips are strikingly white or (rarely) yellow. Two faint light spots may occur at the back of the top of the head. The belly is pale green, yellow, or white and is not marked. The total length of the adults ranges from about 460 to 862 mm (18.1 to 33.9 in.) in the Great Lakes region (Harding 1997). General Distribution Thamnophis sauritus septentrionalis may be found from southern Maine west through New York, southern Ontario, Canada, northern and central Indiana, the Lower Peninsula of Michigan, and some Michigan Islands. Michigan Distribution The Northern Ribbonsnake has not been recorded from the Upper Peninsula of Michigan, although it occurs on Isle Royale, Bois Blanc, and Drummond Islands. It also occurs on Beaver and North Manitou Islands in the Lake Michigan Archipelago. It is widespread in the Lower Peninsula. Lack of collecting might be at least a partial reason for the lack of records of this species in the relatively few Lower Peninsula counties where it has not been reported. On the other hand, disturbance of wetlands in some of the highly cultivated counties might have extirpated populations of Northern Ribbonsnakes there. Geographic Variation As far as I am aware, no distinct populations of Northern Ribbonsnakes have been described in Michigan. Three other subspecies of Thamnophis sauritus are recognized (Crother 2008). Thamnophis s. sauritus

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The Amphibians and Reptiles of Michigan

(Linnaeus 1766), the Common Ribbonsnake, ranges from southern New England west through southern Ohio and Indiana to the Mississippi River and south through the rest of the eastern United States except for southeastern Georgia and peninsular Florida (Ernst and Ernst 2003). Thamnophis s. nitae Rossman 1963, the Bluestriped Ribbonsnake, occurs mainly in the Panhandle area of Florida, and Thamnophis s. sackenii (Kennicott 1859), the Peninsula Ribbonsnake, occurs in peninsular Florida and the Florida Keys.

FIG. 94. Northern Ribbonsnake (Thamnophis sauritus septentrionalis) from Grand Traverse County, Michigan. Photograph by the author.

Habitat and Habits In Michigan, the Northern Ribbonsnake may be found near lakes, ponds, streams, swamps, marshes, and bogs. These sites are enhanced by the presence of clumps of grass and shrubs. Unlike the more methodical Butler’s Gartersnake, the Northern Ribbonsnake is alert, nervous, and very active as it searches for small frogs at the water’s edge. Northern Ribbonsnakes are usually active by day but may also look for frogs at night, especially during the frog breeding season (Ernst et al. 1997). This snake also climbs into low vegetation, where I believe it may hunt for the two Gray Treefrog species in Michigan. Ruthven (1908, 12) described the habitat and habits of the Northern Ribbonsnake as follows: “Like the other members of the group, sauritus seems to be more than ordinarily aquatic in its habits, but apparently less so than either proximus or sackeni. In Michigan we

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have generally found it about the margin of ponds and streams in damp woods. It is somewhat of a climber, and is occasionally found in bushes, several feet from the ground. When pursued it glides through the pools and herbage at an astonishing rate, and does not hesitate to take to the water to conceal itself among the water plants, but it generally remains near the surface, and we have never observed it dive to the bottom like a natricid [water] snake.” It appears that Northern Ribbonsnakes remain within a rather small home range, at least in Michigan. Carpenter (1952a) related that the maximum distance moved between captures was 278 m (303 yd.). The greatest width for any pattern of movement was 49 m (53.4 yd.). In Michigan, Carpenter (1953) found that this snake hibernates in ant mounds, vole tunnels, and crayfish burrows. In the ant mound hibernaculum (see the Butler’s Gartersnake account for particulars about this site), eleven Northern Ribbonsnakes were found at depths ranging from 0 to 5 inches and 14 to 15 inches below the surface. One of the three Northern Ribbonsnakes at the shallowest level was dead. Also in Michigan, Carpenter (1952a) found that young T. sauritus had a lower rate of winter death than did associated Eastern Gartersnakes. Reproduction and Growth Unfortunately, very little has been published about reproduction and growth in the Northern Ribbonsnake as well as the other subspecies of T. sauritus. Carpenter (1952b) reported that southern Michigan female T. sauritus become sexually mature at two to three years of age at a snout-to-vent length of 420 mm (16.5 in.); Burt (1938) stated that female Michigan T. sauritus could reproduce after reaching a total length of about 600 mm (23.6 in.). Young Ribbonsnakes are born from July through September in northern Virginia (Ernst et al. 1997). Langlois (1924) found seven embryos in one female and nine embryos in another in the northern part of Michigan’s Lower Peninsula. Relative to southern Michigan Northern Ribbonsnakes, Carpenter (1952b) determined that the annual period of growth was 153 days between May 1 and September 30, and he found a female that had grown 268 mm (10.6 in.) within two years. A captive-born Northern Ribbonsnake lived ten years, seven months, and twenty-three days at the Brookfield Zoo in Chicago (Snider and Bowler 1992).

2. Species Accounts

Diet There seems to be little doubt that the favorite food of Michigan Northern Ribbonsnakes is frogs. Brown (1979) reported that twenty-one Michigan Northern Ribbonsnakes had eaten only amphibian prey, 93 percent of which were anurans (frogs and toads). Carpenter (1952a), during his extensive study of Gartersnakes in Michigan, found that Northern Ribbonsnakes’ prey consisted of 90 percent amphibians. It appears that small individuals eat small frogs and tadpoles, and larger adults eat medium-sized to large frogs of the genus Rana. Rowe et al. (2000) found that northern Michigan Ribbonsnakes showed a dietary shift from primarily adult spring peepers (Pseudacris crucifer) in early summer to emerging frogs, toads, and salamanders in late summer. They also showed that larger snakes ate larger prey. Minton (1972) reported that his captive Ribbonsnakes refused to eat earthworms. Predation and Defense Ernst and Ernst (2003) reported that wading birds, small mammals, and snakes eat Northern Ribbonsnakes and that the young may be eaten by fishes, large crayfish, and turtles. I have found that in warm weather, Michigan Northern Ribbonsnakes quickly glide away at the approach of a human, sometimes exiting the area through the branches of low bushes. When they are sunning on the road in relatively cool weather in autumn, however, they can often be approached and rather easily taken. When frightened near water, they will quickly move into it, but I have never seen one dive to the bottom. When grasped, this snake may thrash around and spray the antagonist with unpleasant secretions, but I have never had one attempt to bite. Interaction with Humans As far as my experience goes, I have never heard people in Michigan refer to the Northern Ribbonsnake as anything but a “garter” or “garden” snake. It appears that most people do not attempt to kill it. The destruction of wetlands by humans, though, has taken a toll on this harmless, brightly colored species. Behavioral Characteristics For the behavioral characteristics of Thamnophis sauritus, see the sections “Habitat and Habits,” “Diet,” and “Predation and Defense” in this account.

Population Health Where relatively undisturbed aquatic situations—such as lakes, ponds, streams, and various wetland habitats—exist in the Lower Peninsula of Michigan, this species does well. If these situations are highly disturbed, though, this species and most of its natural prey disappear. Ribbonsnakes are not presently listed by the MDNR, but they are considered Endangered in Wisconsin and Illinois, Threatened in the Lower Keys of Florida, and a Species of Special Concern in Connecticut, Kentucky, Maine, Rhode Island, and Virginia. General Remarks The Northern Ribbonsnake is at once the most elegant and specialized of the three Thamnophis species in Michigan.

Thamnophis sirtalis sirtalis (Linnaeus 1758) Eastern Gartersnake Identification The Eastern Gartersnake is the largest and most ubiquitous member of the three Thamnophis species in Michigan. This subspecies is particularly variable in both color and pattern. Usually, it has three light stripes that occur on a background color of black, brown, olive, or gray. The stripes may be of almost any light color and may occasionally be brown. Sometimes these stripes are inconspicuous and may even be absent. When stripes are present, one stripe extends down the middle of the back, and another stripe runs along each of the lower sides, covering the second and third row of scales up from the wide scales of the belly. Quite a few individuals have two alternating rows of dark spots that give them a somewhat checkered appearance. The head is well defined from the neck and is dark above. The lip scales are yellow and sometimes edged in black. The tongue is bright red and has a black tip. The chin, throat, and belly can be so variable in color that they are not of great use in the identification of this subspecies. The scales are keeled, and the anal plate is single. In the Great Lakes region, the total adult length is said to range between 460 to 1,370 mm (18.1–53.9 in.) (Harding 1997). Male Eastern Gartersnakes are generally more gracile than females and have longer tails.

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General Distribution The Eastern Gartersnake ranges from Massachusetts and western New England west through Ontario, Canada, and south through peninsular Florida, and along the Gulf Coast from the Florida Panhandle west to eastern Louisiana. Isolated populations also occur in southwestern Louisiana and southeastern Texas (Ernst and Ernst 2003). Michigan Distribution Eastern Gartersnakes have been documented in every county in Michigan. It is found on Isle Royale and Drummond and Bois Blanc Islands, and they were abundant on Charity Island in 1910 (Thompson and Thompson 1912). Eastern Gartersnakes also occur on Beaver, Garden, High, North Fox, North Manitou, South Fox, South Manitou, Squaw, Trout, and Whiskey Islands in the Lake Michigan Archipelago.

seen actively moving under ice (see Holman 2000, plate 48). Carpenter (1953) found Eastern Gartersnakes hibernating in an ant mound, a meadow vole tunnel, and in a crayfish burrow in southeastern Michigan. Twentysix hibernating Eastern Gartersnakes were excavated from an ant mound in Washtenaw County on February 25, 1951, at depths below the surface of 6 to 7 and 28 to 29 inches. All of these snakes were alive. Three adults of these snakes had been found in a meadow vole tunnel on January 2, 1950, at a depth of 6 to 15 inches, and all were alive. A flooded crayfish burrow that was excavated on February 24, 1951, yielded three live Eastern Gartersnakes at depths between 3 and 22 inches. The cloacal temperatures ranged from 4.2ºC (39.6ºF) in the animals that were 3 inches below the surface level to 5.0ºC (41.0ºF) in the animals that were 21 inches below the surface level.

Geographic Variation Although there is variation in coloration and pattern in Eastern Gartersnakes in Michigan, no distinct populations have been identified. The Thamnophis sirtalis group (Common Gartersnakes) has a huge distribution in North America, occurring throughout southern Canada and the United States except for a few southwestern states. Eleven subspecies (including the Eastern Gartersnake) are recognized. These subspecies have been rearranged in the past (see Crother 2008) and will undoubtedly be rearranged again in the future. Habitat and Habits Eastern Gartersnakes are the most abundant snakes in Michigan. As long as they do not have to travel a long distance to find water, they are likely to turn up in about any habitat in the state. They are able to live in most agricultural, suburban, and urban areas as long as earthworms are available. (They are by far the largest of the “worm-eating” snakes.) Eastern Gartersnakes are probably more cold tolerant than any other snake in Michigan and normally have an annual activity pattern from March to late November. The earliest I have seen these snakes in the Lansing area was March 8, 2000, when I saw three of these animals dead on a road. I have no doubt these snakes appear even earlier in the year than that in this part of Michigan. Sometimes they are

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FIG. 95. Eastern Gartersnake (Thamnophis sirtalis sirtalis) from Kalkaska County, Michigan. Photograph by the author.

Thamnophis sirtalis is exceptionally tolerant to cold hibernation sites and may be frozen for periods of time (Churchill and Storey 1991, 1992). On the other hand, long-time freezing can result in the death of many Gartersnakes in their hibernacula (Bailey 1949; Churchill and Storey 1992). Most T. sirtalis are active when their body temperatures are between 18 and 30ºC (64.4–86ºF), but they look for shelter when their body temperature falls below 17ºC (62.6ºF) (Aleksiuk 1976). In Michigan, about half of the active Eastern Gartersnakes had cloacal temperatures between 25 and 30ºC (77–86ºF) (Carpenter 1956). Rosen (1991b) found that active Eastern Gartersnakes

2. Species Accounts

from Michigan (in the middle of warm, clear days) had body temperatures ranging from 22.6 to 34.4ºC (72.7–93.9ºF). He found that Eastern Gartersnakes under the same conditions in Georgia had body temperatures of 26.9 to 34.3ºC (80.4–93.7ºF). Relative to range, Carpenter (1952a) found that Michigan Eastern Gartersnakes moved no farther than 300 m (327 yd.), with most movements being less than 183 m (199.5 yards). Carpenter thought the average Eastern Gartersnake home range was about 0.8 ha (1.98 acres). Reproduction and Growth Sexual maturity probably occurs at different snout-tovent lengths in the different subspecies of Thamnophis sirtalis. Rossman et al. (1996) indicated that males of this species become sexually mature within a year or two at a snout-to-vent length of 360 to 390 mm (14.2–15.4 in.). They concluded that females are sexually mature in two to three years at a snout-to-vent length of 420 to 550 mm (16.5–21.7 in.). A small Eastern Gartersnake 438 mm (17.2 in.) in total length from Wexford County, Michigan, taken in May 2003, later gave birth to one living and ten dead young snakes between August 11 and 21. The dead young were all in their fetal membranes and not completely developed. The one survivor was emaciated and tiny and was fed a diet of diced earthworms until healthy. The emaciated female was nourished back to health on a diet of earthworms, minnows, and diced fish and was released on August 20, 2004. The surviving young snake was released in the wild on June 15, 2005, at a total length of 266 mm (10.5 in.), apparently very healthy. I have no idea why the one surviving snake had become so much more fully developed than the ten that were aborted. In Michigan, Eastern Gartersnakes usually begin mating during or directly after emergence from their winter hibernacula in late March or early April. Sometimes a veritable tangle of males can be found attempting to court one or two females. Such congregations often give off an odor that can be detected several feet away before the snakes themselves are actually spotted. The males are frantic and have what is to me a characteristic fixed look in their eyes that is difficult to describe. The actual courtship and breeding of Eastern Gartersnakes is not as complex as it is for other species

of Michigan snakes. Ruthven (1908) characterized part of the process in two captive specimens from southern Michigan, which I have paraphrased here. The male lies at full length next to the female and attempts to excite her by gently rubbing her neck with his snout. At length, he throws a fold of his tail across hers and turns his ventral surface against her side, beginning spasmodic contractions of his abdominal muscles. This can continue for twenty to thirty minutes. The female role (which Ruthven left out) is rather passive, but hemepenial insertion by the male can occur only if the female raises her tail to expose her gaping vent (Ernst and Ernst 2003). After mating, female T. sirtalis will not mate with other males, as the male that she has already copulated with has placed a copulatory plug in her cloaca. This plug blocks her reproductive duct for several days. The plug is apparently formed by male kidney secretions, and its function may be to prevent rival males from copulating with the female (Devine 1975, 1977; Ross and Crews 1977). Thamnophis sirtalis females are able to store sperm from spring or fall matings over the winter; these sperm may remain active for a year (Fox 1956). Eastern Gartersnakes (and all subspecies of T. sirtalis) give birth to live young. Nourishment comes to the developing snakes by way of a placenta-like structure. About Eastern Gartersnakes in the Great Lakes region, Harding (1997, 273) stated that “most Great Lakes area females give birth in August or early September (range from late July to early October). The young are usually born enclosed in a thin membrane, from which they soon wriggle free. Litter size ranges from three to eighty young (most often from ten to forty) and is directly related to the size of the female.” Carpenter (1952b) indicated that a period of 153 days from May through September is considered the time of growth for the Eastern Gartersnake in Michigan. He also pointed out that the growth rate in Eastern Gartersnakes constantly decreases the larger these snakes become, particularly after sexual maturity is reached. Diet Unlike the slow, chubby Butler’s Gartersnake that feeds mainly on earthworms and snails, and the fast, slender, and alert Northern Ribbonsnake that prefers amphibian food and chases small frogs about, Eastern Gartersnakes

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are the consummate generalists in their feeding habits. Some of the common items that this snake feeds on are fishes, frogs, toads, salamanders (both terrestrial and aquatic), small snakes, small birds, shrews, young chipmunks, mice and voles, earthworms, leeches, slugs, snails, millepedes, isopods, and various adult and larval insects (simplified from Ernst and Ernst 2003, 435). Gillingham (pers. comm.) induced a large Gartersnake to regurgitate a young snowshoe hare (Lepus americanus) on Beaver Island, Michigan. Carrion is also readily eaten. I have observed that when Eastern Gartersnakes forage in shallow water, they often do so with their mouth open and head slashing randomly about (author’s observations). In 1947 I watched Eastern Gartersnakes swimming along the shoreline of Lake Paradise (near Mackinaw City) foraging for food on warm, calm days. The prevailing southwest wind brought dead fish to the edge of the beach. Each day I observed them, one or two large Eastern Gartersnakes would explore each dead fish, which were mainly large rock bass and white suckers. These snakes harvested leeches that they tugged off the dead fish and rapidly swallowed. The snakes then moved along down the beach. Another feeding behavior I have noticed many times in captive hatchling, juvenile, and young adult Eastern Gartersnakes (as well as Butler’s Gartersnakes) is tail lashing. This behavior occurs when a snake is swallowing food. When a Gartersnake is swallowing food alone, tail lashing is rarely seen. But if other Gartersnakes approach, the snake that has food will violently lash its tail, which often distracts the intruding snakes. If two neonate (newborn) Eastern Gartersnakes seize a worm at the same time, mouth to mouth, one is likely to swallow the other one along with the worm. Both Michael J. Benton and I monitored a large group of neonate Eastern Gartersnakes, all born from a large female near East Lansing, Michigan, in 1979. We fed them on a diet of small earthworms. When we noticed a reduction in the population of neonates, we found that several of the large ones had eaten the smaller ones. Later I rescued two that were “going down the hatch” of somewhat larger neonates. In each case, both snakes were trying to swallow the same earthworm. Evidence exists that the saliva of Thamnophis sirtalis has venom-like properties. Secretions from the gland that

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produces this saliva may be lethal to mice (Rosenberg et al. 1985). When a T. sirtalis bites, it may deeply embed its rear maxillary teeth into the hand holding it. This can cause profuse bleeding. Ernst and Ernst (2003) suggested that it is strongly possible that the enzymes in the saliva of this species might help to immobilize active prey such as frogs because these snakes will often continue to chew after they grasp such prey. However, I have been bitten only a few times in many encounters with Eastern Gartersnakes. Each time I experienced only slight bleeding and was never chewed upon. I had no reactions from any of the bites. I have never been bitten by a neonate or juvenile Eastern Gartersnake. On the other hand, I once handled a small juvenile San Francisco Gartersnake (Thamnophis sirtalis infernalis). This little snake immediately seized the skin of the first joint of my thumb and began to chew vigorously. The chewing itself was sharply painful, on the order of being stung by a bee, and my thumb became swollen for an hour or so, although the initial pain soon subsided considerably. The bite area itself remained sensitive for two days. In 1988 I talked with a Michigan physician who was treating a young boy who had been bitten on the hand by a medium-sized Eastern Gartersnake. The boy had rather upsetting allergenic symptoms for a time, but he recovered with no complications. Predation and Defense Predators of Eastern Gartersnakes in the Great Lakes region and Michigan would likely be large fishes such as bass and pike; amphibians and reptiles such as American Bullfrogs, Eastern Snapping Turtles, and various snakes such as Eastern Milksnakes, Blue Racers, and Massasaugas; birds such as crows, turkeys, hawks, and herons; and many mammals such as shrews, weasels, skunks, foxes, raccoons, and even domestic cats and dogs. Humans kill Eastern Gartersnakes both accidentally and on purpose. The work of Ernst and Ernst (2003, 436) contains a comprehensive list of predators of the species Thamnophis sirtalis. When attacked, Eastern Gartersnakes normally glide away quickly, their striped body helping to disguise and confuse would-be predators. If these snakes are cold or cornered, they will often flatten and strike. If they are grabbed, they will smear a smelly musk on their antagonist and may bite.

2. Species Accounts

Interaction with Humans Eastern Gartersnakes are much more often killed by humans than the other two Thamnophis species that occur in Michigan. I imagine the reason is that this is a much larger snake and when it is cornered or cold, it will sometimes coil, extend its bright red tongue tipped with black, and may make short strikes at the beholder. The faintly striped, brownish specimens and the stripeless individuals fare much worse. Ernst and Ernst (2003) discussed in detail a thirteen-year-old who suffered more than the boy described in the “Diet” section of this account. After an Eastern Gartersnake chewed on his index finger for several minutes, this lad had symptoms that led to hospitalization. I would suggest that when handling this snake, playing it safe and wearing gloves would be wise; perhaps better yet, handling these snakes should be left to experienced herpetologists. Behavioral Characteristics For the behavioral characteristics of Thamnophis sirtalis sirtalis, see the sections “Habitat and Habits,” “Reproduction and Growth,” “Diet,” “Predation and Defense,” and “Interaction with Humans” in this account. Population Health The Eastern Gartersnake is the most abundant snake in Michigan and is not listed by the MDNR. If environmental conditions continue to deteriorate in the state, this will probably be the last snake to be extirpated. General Remarks Thamnophis sirtalis, because of its abundance in so many states, is the most widely studied snake in the United States. Yet many more problems regarding this species still need to be solved. For instance, it would be very interesting to know the various properties in the saliva of the different subspecies of this snake. It also would be interesting to know whether Eastern Gartersnakes in Michigan voluntarily break off their tails to escape predators, as they do in South Carolina (Cooper and Alfieri 1993), or play dead as they do in Ontario (Schueler 1975).

Family Viperidae The Viperidae are venomous snakes that occur in Africa, Asia, Europe, and the Americas exclusive of cold areas. Thirty-two genera and 223 species have been recognized in this family by the Herpetologists’ League (McDiarmid et al. 1999). The mechanism for poison injection in viperids is the most advanced of any group of venomous species in the world. The maxillary bones in the upper jaws are shortened and capable of movement that allows the very long, hollow fangs to be rotated so they lie against the palate and the mouth can be closed over them. When these snakes strike, the fangs rotate forward into a stabbing position. The venom of viperids mainly attacks the circulatory system, but some species have a venom that attacks the nervous system as well. The pupils in the eyes of these snakes are vertically elliptical as in the eyes of cats. All of the vertebrae in the main part of the body have long structures called hypopophyses that point downward from them. The body scales are keeled. Four subfamilies occur in the Viperidae, but only one subfamily, the Crotalinae, occurs in the Americas. The Crotalinae have deep sensory pits between the eyes and nostrils. Michigan has only one truly venomous snake, the Eastern Massasauga, a rattlesnake. Although some Michigan snakes will vibrate their tail when disturbed, none have true segmented rattles except the Massasauga.

Sistrurus catenatus catenatus (Rafinesque 1818) Eastern Massasauga Identification The Eastern Massasauga is the only Michigan snake that has a true segmented rattle on the end of its tail and a deep opening between the eye and the nostril called a “pit.” This snake is thick and heavy-bodied, and it has vertical, elliptical pupils like those of cats. It is rather dark in color and has a row of about twenty to forty large, dark brown blotches edged in black, white, or pale yellow, running down the back. Two or three rows of dark spots alternate along the sides. The background color is gray, grayish brown, or brown. The head distinctly widens in front of the neck. A dark stripe, bordered below by a white stripe, extends from the eyes toward the rear of the head. The species Sistrurus catenatus grows to a total length of 1,003 mm (39.5 in.), but most

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individuals are shorter than 550 mm (21.7 in.) (Ernst and Ernst 2003). Males have a longer tail than do females. General Distribution The Eastern Massasauga occurs from western New York, western Pennsylvania, and southern Ontario, Canada, west to eastern Iowa and Missouri. Michigan Distribution The Eastern Massasauga has not been reported from the Upper Peninsula, but it occurs on Bois Blanc Island and was reported to occur on Charity Island by Ruthven et al. (1928). It is widespread in the upper and lower thirds of the Lower Peninsula, but county records are spotty in the middle third. I am not sure why records of this species are this way in the middle of the Lower Peninsula, but I would guess the reason is the draining of marshes and swamps for agricultural purposes. After the draining in the mid-twentieth century of the extensive Chandler Marsh near Lansing, Michigan, to create sod farms, the zoology faculty at Michigan State University received frequent calls about this species in the ditches around the farms. I would see one or two per year that had been killed on Chandler Road next to these ditches. I have not had a call about this species in ten years and have not seen a dead specimen on this road in fifteen years.

Geographic Variation I am not aware of any studies that indicate Eastern Massasaugas may have distinct populations in Michigan. Two other subspecies, which live outside of Michigan, are recognized: Sistrurus c. edwardsii (Baird and Girard 1853), the Desert Massasauga, and S. c. tergeminus (Say 1823), the Western Massasauga. Habitat and Habits In Michigan, the Eastern Massasauga is partial to habitats that have wetland situations with nearby upland areas. The wetlands include river bottomlands, shrubby swamps, marshy borders, and shrubby peatlands. These kinds of habitats are used by the snakes from September into June. Eastern Massasaugas hibernate singly in mammal or chimney crayfish burrows. The snakes emerge in April as water levels rise. Following hibernation, they tend to occupy grass and sedge communities where they can either bask or hide. When they are hiding in the grass, they are very difficult to see, even from just a yard or two away. Researchers who have monitored movements of this snake by means of implanted radios have received signals that they are on top of an individual and have spent anxious minutes looking into clumps of grass for these animals that are hidden literally under their feet. In the early summer, many Michigan Massasauga move into adjacent uplands where they spend the summer foraging for mice, voles, and other prey in open, shrubby

FIG. 96. Eastern Massasauga (Sistrurus catenatus catenatus) from Michigan. Photograph by James H. Harding.

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2. Species Accounts

areas, including pastures and hay fields. During these movements from lowland to upland situations and back, these snakes may be seen in the vicinity of farmhouses or suburban yards. In Ontario, Eastern Massasauga home ranges averaged .25 square kilometers (.16 square mile) (Weatherhead and Prior 1992). Mean distances that the snakes had moved per day were 7 to 167 meters (7.6– 182.0 yd.) and per season were 752 to 3,712 meters (819.7–4,046.1 yd.). Pregnant females traveled less distance than either nonpregnant females or males (Johnson 2000; Weatherhead and Prior 1992). Moore and Gillingham (2006) studied the Eastern Massasauga in southern Michigan and found them to have home ranges averaging 1.3 ha (3.2 acres) and that they moved an average of 6.9 m (22 ft.) per day. In Wisconsin, newborn Massasaugas have the smallest home ranges, and they also move a lesser distance per day than juveniles or adults (R. S. King 1999). Massasaugas are reasonably good swimmers. About Eastern Massasaugas in southern Michigan, Ruthven et al. (1928, 131) stated that “it prefers the vicinity of swamps, although not aquatic in its habits, and is becoming yearly more rare in this region. Its extinction is probably due to several causes, chief of which is the draining of swamps and the killing of great numbers by farmers.” Hallock (1991) used radio tracking to observe spatial patterns, behavior, and hibernation sites in southern Michigan and reported that the snakes were found to inhabit upland, grassy areas in the summer and lowland, poorly drained habitats in the fall. All of the snakes studied hibernated in mammal burrows. She stated that “once a hibernating site was established the snakes came out to bask but would rarely venture more than a half meter from the entrance of the hibernating site. Near the opening to the burrow, the snakes were cautious and retreated into the burrow when approached. The snakes appeared cautious when leaving the burrows. At times they were observed to have half of their body outside of the burrow and the other half inside. At other times only the head was exposed and a great deal of tongue flicking was observed. The snakes were still coming to the surface on October 31, 1990, on days when the temperature was above 50ºF” (17–18). In southeastern Michigan, ten of eleven Massasaugas hibernated in crayfish burrows, often submerged in water (Moore 2004).

Relative to the Chicago area, C. H. Pope (1944, 222) wrote that “remarkably little has been written on the massasauga’s habits. It is often seen abroad during the day, and in early spring numbers may be found basking on tufts of grass in their swampy habitat. I have noticed in the Chicago area that August is a period of activity— during this month these snakes are most often seen crossing Portwine Road, between Deerfield and Dundee Roads. The significance of this summer activity is not clear.” Minton (2001, 351) stated that “information from Pokagon State Park [in northern Indiana near the Michigan border] indicates that most snakes are found there during August. Farmers usually find the snakes when haying, threshing, or clearing new ground. They are more often found in the open coiled in the sun or crossing roads than under cover.” Reproduction and Growth Massasaugas breed in the spring and then again in the later part of summer or in the fall. The partial description of breeding that follows is paraphrased and condensed from an account presented by Ernst and Ernst (2003). The male lies on the back of the female with his tail wrapped around hers, frequently rubbing her head and neck with his chin and writhing his body. He then stimulates the female by tightening his tail loop and alternately stroking forward and backward, the entire act being repeated several times. The chin-rubbing continues during the tail strokes. When mating takes place in the late summer or early fall, the young are not born until the following spring. (Like the gartersnakes, watersnakes, and brownsnakes, Massasaugas also give birth to their young rather than laying eggs.) Most births occur in August following spring breeding, and litters average about eight young. However, Moore (2004) observed parturition for nine Massasaugas in southeastern Michigan between September 20 and October 10. Seigel and Fitch (1984) reported that among fifty-three newborns, they had total body lengths from 135 to 275 mm (5.3–10.8 in.) with a mean of 212 mm (8.3 in.). Yearling Eastern Massasaugas studied in northeastern Illinois had total body lengths of 390 to 430 mm (15.4–16.9 in.), which represented an increase in size from birth of about 65 percent (B. A. Wright 1941).

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The Amphibians and Reptiles of Michigan

A male Massasauga lived for twenty years and five days at the Staten Island Zoo (Snider and Bowler 1992). Diet Hallock (1991) conducted a dietary analysis of 125 preserved snakes from the Museum of Zoology at the University of Michigan and the Michigan State University Museum. All the specimens came from southern Michigan. Of the 125 specimens examined, 43 (34.4 percent) contained at least one food item. Most of these items (77.3 percent) were mammals, and of these, 68.4 percent were voles (Microtus sp.). Snakes made up the next largest group (15.6 percent). Birds (4.4 percent) and insects (4.4 percent) were each found in two specimens. One frog (2.2 percent) was also recorded. Insect remains were incidental bits and could have been in the stomach contents of the prey items. Ruthven et al. (1928) found a snake in an Eastern Massasauga that was possibly eaten as carrion. In Wisconsin, Keenlyne and Beer (1973) found that 95 percent of the prey of Eastern Massasaugas consisted of warm-blooded animals and that 85.7 percent of them were voles. Only one snake prey item was found, and it made up only 1.1 percent of the diet. Eastern Massasaugas mainly lie in wait for their warm-blooded prey, but they also do some active hunting (Ernst and Ernst 2003). Schuett et al. (1984) reported that young Sistrurus catenatus wave their tails back and forth over their heads as a color lure to catch small frogs. Predation and Defense Accounts of predation on Massasaugas are few. In the University of Michigan Museum of Zoology, a large Michigan Blue Racer is preserved in the process of swallowing a mature Eastern Massasauga. Relative to Eastern Massasaugas in the Great Lakes region, Harding (1997) suggested that some birds, such as herons and owls, and that some mammals, such as raccoons and foxes, are able to kill these snakes at times. But C. H. Pope (1944, 224) had already cast some doubt as to whether this might happen when he related that “I made a crude experiment with a pet raccoon that had never before encountered a rattlesnake and concluded that the sound of the rattle put the raccoon on guard and kept it from approaching the massasauga as unhesitatingly as it approaches a garter snake.” In a radiotelemetric study of Massasaugas in southeastern Michigan, Moore (2004)

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retrieved a radiotransmitter from one of her specimens from an owl’s nest. This seems to indicate that not only can owls prey on Massasaugas but that these snakes may be active at night. Ernst and Ernst (2003) related that habitat destruction and road killing of Massasaugas by humans probably destroy more of these snakes in a year than all of its combined predators. Minton (2001) stated that hogs appear to have played an important part in extirpating the Massasauga from many places in the Midwest. If attacked, Eastern Massasaugas usually respond by striking at the attacker with no hesitation. Its venom is potent enough to seriously injure or even kill mammalian predators the size of foxes and raccoons. This is the best active defense of this species. A large dog was reportedly struck by a Massasauga in Michigan and subsequently died. I heard this reported on two radio stations in southern Michigan but was never able to follow up. Most dogs that have been bitten by this species in the Great Lakes region have survived (Harding 1997). Whatever the more frequent result of a bite to a dog may be, please do not let your dog loose in Massasauga habitat. The best passive defense this snake has is its remarkable ability to hide in grassy areas, as previously mentioned. Interaction with Humans Ernst and Ernst (2003) reported that Massasaugas are somewhat sluggish and mild mannered and that they strike only when provoked. On the other hand, this is not a snake to be taken for granted at all. Minton (2001, 351–52) put it this way: “Most collectors report these snakes as sluggish, inoffensive, and slow to rattle. This has not been my impression of those I have had in captivity. Nearly all have been alert, bad-tempered snakes, quicker to strike than several species of larger rattlesnakes. In the Midwest, Massasaugas account for many more snakebites than the Timber Rattlesnake. While the Massasauga is often considered not highly dangerous, its venom is more lethal than that of most rattlesnakes, and there are well-authenticated fatalities from its bite, one of them occurring in Indiana (Lyon and Bishop 1936),” and fatalities have occurred in Michigan also, albeit mostly in the late nineteenth century, when the snakes and their habitats were more common and medical care was less effective (J. Mahaffy

2. Species Accounts

and Thomas Beauvais, pers. comm.). When hiding in clumps of grass, Michigan Eastern Massasaugas are loathe to rattle or move, even when a person is close by. I have no doubt, however, that if a person stepped on this snake, it would strike without hesitation. When I have encountered this snake on the move in the open, I have found them as bad tempered and quick to strike as any of several species of rattlesnakes I have encountered out in the field in Florida, Texas, and Indiana. I was informed of two Eastern Massasauga bites that occurred along a nature trail on a reserve in southeastern Michigan during a single summer during the late 1980s. One person wearing open shoes was bitten on the foot. Another person picked up a severed head and partial neck of a “dead” Massasauga to examine the specimen. The head, on its neck stump, twisted around and bit the person on the thumb. Fortunately, both of these people recovered without losing a toe or finger. Other than the rare bite that they inflict on humans or their pets, these very interesting rattlesnakes are an important part of the ecosystem. They are undoubtedly helpful to farmers in rodent control. Behavioral Characteristics For the behavioral characteristics of Sistrurus catenatus catenatus, see the sections “Habitat and Habits,” “Reproduction and Growth,” “Diet,” “Predation and Defense,” and “Interaction with Humans” in this account.

In Kansas, observations of dominance bouts between Massasauga males were described by Collins and Collins (1993). The males face each other with their heads and the upper portion of their bodies elevated. The vent areas are pressed together and their necks are twisted around each other. Each male tries to pin the head of his opponent to the ground. Population Health Populations of Massasaugas are on the decline in Michigan as well as in the Great Lakes region (Harding 1997). Michigan appears to be a stronghold for this uncommon snake, which is threatened or endangered over much of its range. This species is listed as a protected Species of Special Concern by the MDNR. To ensure the long-term survival of this interesting species, the Michigan Natural Features Inventory (MNFI) is conducting surveys to determine how to achieve this goal. General Remarks The earliest pit viper remains in North America are fossils from the Early Miocene (24 to 20 Ma BP) from western Nebraska. These remains appear to be almost identical to the genus Sistrurus (Holman 2000).

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3

Quaternary Remains of Michigan Amphibians and Reptiles

Introduction This part of the book deals with Michigan amphibian and reptile remains that have been excavated from Quaternary paleontological and archaeological sites in Michigan. The Quaternary period represents the last 1.8 million years before the present (Ma BP). The Quaternary period itself is divided into two epochs: the Pleistocene epoch or “Ice Age” (1.8 million to 10,000 years ago) and the Holocene epoch (10,000 years ago to the present). Michigan amphibian and reptile remains have been found only in the last few thousand years of the Pleistocene and the Holocene. The reason is that much of the Michigan vertebrate fossil record from the end of the Pennsylvanian period to the late Pleistocene (about 290 million years to about 50,000 years ago) was eliminated by erosion of an uplifted Michigan as well as by the scouring effect of the Pleistocene glaciers (Holman 1995a). The evolution of the modern species making up the herpetofauna of Michigan took countless millions of years. Plants and animals did not become truly diverse until the Cambrian period about 540 Ma BP. Four-legged vertebrates (tetrapods) did not evolve from fishes until the Late Devonian period about 360 Ma BP. Salamanders, frogs, and turtles appeared by the end of the Triassic period about 206 Ma BP. True lizards appeared during the Jurassic, which lasted from the end of the Triassic until about 144 Ma BP. Snakes were the latecomers, appearing for the first time in the Cretaceous, about 100 Ma BP. The ancestors of our own amphibians and reptiles, as you can see, go back a long, long way. Many of the genera and even species of Michigan amphibians and reptiles have been around a long time,

as represented by fossils found in other parts of North America (Holman 1995b). Necturus (the Mudpuppy genus) and Apalone (the softshell turtle genus) are both known from the Paleocene epoch, which lasted from 65 to 54.8 Ma BP. Later, in the Eocene epoch, about 35 Ma BP, Ambystoma (the Mole Salamander genus) and Hyla (the Treefrog genus) are known from Saskatchewan, Canada. The Skink genus (Plestiodon) is known from the Oligocene epoch, about 25 Ma BP. The Miocene epoch that ranged from 23.8 to 5.3 Ma BP produced fossils of the Lungless Salamanders (genus Plethodon), the toad genus (Bufo), and the modern turtle genera Chelydra (Snapping Turtles), Chrysemys (Painted Turtles), Emydoidea (Box Turtles), and Sternotherus (Musk Turtles). Snake genera present in the Miocene included Heterodon (Hog-nosed Snakes), Diadophis (Ring-necked Snakes), Coluber (Racers), Pantherophis (Ratsnakes), Lampropeltis (Kingsnakes), and Nerodia (Watersnakes). During the Pliocene (5.3 to 1.8 Ma BP), the North American herpetofauna became essentially modern, with many existing species being known in the fossil record (Holman 1995b).

Pleistocene Fossil Sites The Late Pleistocene (Wisconsinan) glaciation in Michigan left thousands of kettles and other glacially derived basins in its wake. These features first filled with essentially sterile glacial meltwater, but with the passage of time they developed into ponds that supported biological assemblages of bacteria, single-celled organisms (protists), fungi, and true plants and animals. Eventually, these ponds filled in by natural ecological processes. Such infilled Pleistocene kettles and basins depict the succession stages from the birth to the death

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The Amphibians and Reptiles of Michigan

of these ponds (see Holman 2001a). The organically rich layers of these infilled structures normally yield the fossil remains of seeds, nuts, leaves, sticks, barks, and bits of broken tree limbs (sometimes even the remains of wood gnawed by fossil beavers) as well as snails and small clams by the thousands. Fossil beetle wings and other bits of insects are occasionally found in such sites. Oddly, although vertebrate fossils are relatively rare in these deposits, huge elephant-like mammals, the mastodonts and the mammoths, are the most numerous vertebrates found (Holman 1995a). Other large, extinct mammals, such as giant beavers and extinct musk oxen, are found in these sites in Michigan but more rarely than mastodonts and mammoths. Small vertebrate animals, including amphibians and reptiles, are exceedingly rare in Michigan Pleistocene kettle and other shallow basin sites. In fact, only frogs and turtles have been found in such situations. Several ancient “great lakes” existed in Michigan in the prehistoric part of the Quaternary period. These older lakes differ in their conformation from those of the present Great Lakes and have been given separate names (see Dorr and Eschman 1970). Inland shoreline structures of these Pleistocene lakes can be identified and dated on the basis of their stratigraphic position and from time to time can be identified during the digging of water wells. A fossil toad was found in such a situation. All of the Pleistocene sites in Michigan that have yielded unquestionable remains of fossil vertebrates occur south of the Mason-Quimby Line in the southern part of Michigan (see fig. 9).

The Nature of the Fossils All of the Michigan Quaternary amphibian and reptile fossils are based on the fragmentary skeletal remains of the original animals. Fossil amphibian remains are rare in Michigan and the entire Great Lakes region as well (Holman 1995a). This is somewhat surprising since wetlands were abundant in Michigan in the Late Pleistocene as well as during the cooler intervals of the Holocene. On the other hand, amphibian fossils are very small and fragile. Frogs and toads have hollow bones that are likely to break into pieces not only when they are in the ground but when they are excavated by paleontologists. It is also very difficult to wash and screen the fibrous sediments of the kettle bog and shallow basin sites in the state. In all of the amphibian groups, certain bones are much more reliable for identification purposes than others. For example, salamander vertebrae (segments of the backbone) are relatively sturdy and have complicated processes on them that distinguish one genus or species

Holocene Fossil Sites Holocene fossil sites in Michigan have yielded many more amphibian and reptile remains than have those of the Pleistocene. Holocene fossil sites in Michigan may occur in natural deposits of muck, peat, lake beds, and dunes, and in the Upper Peninsula, in rock fissure fills and small caves. Some of these Holocene sites represent relatively cold intervals, whereas others indicate warm, dry spells. All of the fossils found in Michigan Holocene fossil sites represent species that still live in Michigan today. Because faunal remains in archaeological sites are intertwined with human activities, accounts of amphibians and reptiles from archaeological digs are presented in a separate section.

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FIG. 97. Vertebra of a Mole Salamander (Ambystoma) from the Pleistocene in five views: (A) dorsal, (B) ventral, (C) anterior, (D) posterior, and (E) lateral. The numerals label the (1) neural spine, (2) prezygapophyseal accessory facet, (3) postzygapophyseal accessory facet, (4) bottom of the centrum, (5) rib-bearing process, (6) anterior cotyle, (7) posterior cotyle, (8) neural canal, and (9) lateral wall of the neural arch. Illustration by Rosemarie Attilio.

3. Quaternary Remains of Michigan Amphibians and Reptiles

FIG. 98. Left ilium of a Green Frog (Rana clamitans) from a modern skeleton: (1) dorsal acetabular expansion, (2) dorsal prominence, (3) border of acetabulum, (4) ilial crest or blade, (5) ilial shaft, and (6) ventral acetabular expansion. Illustration by Donna R. Holman and Jane Kaminski.

from another (see fig. 97). If salamander jawbones with teeth survive the fossilization process, they too are used for identification purposes. The humerus (upper arm bone) of newts and mole salamanders are relatively stout and have diagnostic processes on them. The bone most widely used for the identification of frogs and toads

is the ilium (a horizontally situated bone of the hip). Figure 98 depicts an ilium of a frog (compare fig. 98 with fig. 102, which shows a toad ilium). Other bones widely used in the identification of frogs and toads include the sacrum (the bone that joins the hip to the vertebral column) and the maxillary bone (upper jaw), especially if the maxillary bone bears teeth. Among the reptiles, individual bones of the turtle shell are very useful in the identification of turtle fossils. The shell bone most often used by the vertebrate paleontologist is the nuchal bone (fig. 99) of the upper carapace (upper shell), and the entoplastron of the lower shell (plastron). The humerus is also a good bone for identification of fossil turtle remains in some cases. Fossil lizard remains have not yet been identified from the Quaternary in Michigan, but when remains of this group are unearthed, the most useful bones for identification purposes will probably be the maxilla (an upper jaw bone) or the dentary (a lower jaw) with the teeth attached. Finally, fossil snakes are identified mainly on the basis of vertebrae (fig. 100), of which, incidentally, they have plenty. Snake vertebrae are very complicated and have many processes that aid in the identification of both the genera and species in this legless group. The vertebrae that are most commonly used for identification come from about the middle of the backbone.

Digging the Fossils

FIG. 99. Pleistocene nuchal bones (in dorsal view) that are characteristic of various North American turtle taxa: (A) Sternotherus odoratus, (B) Chelydra serpentina, (C) Kinosternon flavescens (does not occur in Michigan), (D) Terrapene ornata (does not occur in Michigan), (E) Emydoidea blandingii, (F) Trachemys scripta, (G) Graptemys geographica or kohni (do not occur in Michigan), and (H) Chrysemys picta. Illustration by Robert Preston, from Preston (1979), courtesy of the University of Michigan Museum of Paleontology.

Pleistocene and Holocene amphibians and reptiles are rare in Michigan. Their bones are small and fragile. The infilled, glacially derived kettles and shallow basins of the Michigan Pleistocene as well as the old peat bogs of the Holocene contain sediments that are highly acidic. This acid breaks down the calcium-phosphate portion of bones to such a degree that the fossils are in a soft, rubbery state when excavated, or more commonly, completely destroyed. The soft fossils need to be treated with hardening materials to be saved for storage and study. The usual way to obtain vertebrate fossils in Michigan is to probe into soft sediments such as muck or peat to see if bones are there or to immediately dig out soil if bits of bone are found on the surface of more solid sediments. The tools of the trade used to find vertebrate fossils in Michigan are depicted in

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The Amphibians and Reptiles of Michigan

FIG. 100. Vertebra of Lampropeltis pyromelana, a “typical” colubrid snake: (1) dorsal view, (2) ventral view, (3) anterior view, (4) posterior view, and (5) lateral view. Abbreviations: cn, condyle; co, cotyle; hk, hemal keel; na, neural arch; nc, neural canal; ns, neural spine; po, postzygapophyseal articular facet; pr, prezygapophyseal articular facet; pra, prezygapophyseal accessory process; sf, subcentral foramen; sn, synapophysis; sr, subcentral ridge; zg, zygantral articular facet; zr, zygosphenal roof; zy, zygosphenal articular facet. Illustration by Jane Kaminski.

figure 101. Seven-foot-long probes are used to poke into boggy sediments to see if bone is present. A rock struck by the sharpened end of such a probe feels hard and makes a “chink” sound. A piece of wood struck feels much softer and makes a “thunk” sound. A bone feels and sounds somewhere in between. A fossil hunter soon learns how to use this technique to find bones. After

FIG. 101. Some tools used for collecting vertebrate fossils: (A) screen, (B) pick, (C) geological hammer, (D) pry bar, (E) round-nosed shovel, and (F) probe. Illustration by Teresa Petersen.

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bones are located in these soft sites, they are carefully dug up with shovels. Finding tiny amphibian and reptile bones is another matter, and probing for them would be like looking for a needle in a haystack. To find these little bones, the technique is to transport sacks of mucky, fibrous material back to the laboratory and dry it thoroughly. Then it must be picked through. If it is possible to screen this fibrous material, which it usually is not in Michigan, then the matrix (the fossil-bearing material) must be sieved in water and the concentrated bits dried until they can be picked through. A few small cave and fissure sites in the Upper Peninsula of Michigan have yielded small Holocene vertebrates, including a toad and a frog. This cave material is a sandy clay that usually must be dug out with a short pick (called a “geological hammer”) or pocket knife. Crowbars are useful for moving slabs of rock that have fallen onto the matrix on the cave or fissure floor. The matrix is then scooped up, put in small sacks, and taken to the lab where it is sieved, dried, and picked through. To identify the fossil pieces, it is essential to have disarticulated amphibian and reptile skeletons available as comparative material.

Dating the Fossils The most scientifically important Pleistocene and Holocene vertebrate fossils are those that have absolute dates. Radiocarbon dating (carbon-14 method) is the most commonly used method for the absolute dating of vertebrate fossils in Michigan. This method is accurate to about 50,000 years ago. Radiocarbon dates are based on the fact that plants incorporate small amounts of unstable isotopic carbon-14 in their tissues. Plants are the producers at the base of the food chain, so plant C-14 is incorporated into animals at the higher feeding levels (for instance, corn to pigs to humans). When a plant or animal dies, C-14 is no longer incorporated into its tissues, and the leftover C-14 is gradually lost through the process of radioactive decay. So, if the amount of C-14 in a sample of previously living tissue is measured, the time that has passed since the organism died can be calculated. Radioactive decay decreases the C-14 by half at regular intervals, so usually not enough is left to measure after 50,000 years. All kinds of organic material may be used to

3. Quaternary Remains of Michigan Amphibians and Reptiles

obtain radiocarbon dates, but the most common tissues presently used in Michigan are wood and bone. Historically, wood has been used more than bone, but lately bone dates have become more common than they used to be because of more sophisticated methods. To obtain bone radiocarbon dates, two components of bone have been used. Collagen, the protein that gives bone its tensile strength (stretchability), is usually the most dependable of the two, yet the tendency of collagen to weather out of bone in certain situations is problematic. For example, the partial skull with horns of an extinct musk ox that had laid in sediments in a Michigan lake since the Pleistocene was once submitted for radiocarbon dating. However, the research team was disappointed to learn that most of the collagen had leached out of the skull so a radiocarbon date could not be obtained on the fossil. Still, bone dates are generally much more accurate than they used to be because methods for extracting collagen and removing organic contaminants have vastly improved. Fossil wood has such a high organic content that it often attracts other organisms, such as mold or the tiny roots of plants. Abnormally recent dates may be obtained when excess carbon has been added to fossil wood by invasion of roots or mold. Also, a dating problem in very young Holocene sites (sites a few hundred years old) is caused by the atmosphere’s containing an abnormally high amount of carbon during the last few hundred years. Thus, new calibration techniques have been recently employed to obtain more accurate dates. Nevertheless, a rather large margin of error is still necessary after these calibrations. In the accounts of various fossil amphibians and reptiles in Michigan, I discuss any questionable dates that may have been obtained.

Records from northern Indiana and southern Michigan have allowed a reconstruction of the vegetation of the area soon after the final retreat of the ice 14.8 ka BP (Kapp 1999). Treeless marsh and muskeg vegetation existed in the southern part of the Lower Peninsula of Michigan at this time in a background of extensive wetlands. By 13.8 ka BP nearly half of the Lower Peninsula was free of glacial ice. Tundra and boreal vegetation was present at this time in Wintergreen Lake in Barry County in southwestern Michigan (Kapp 1999). This is about the time that the earliest Pleistocene amphibian or reptile fossil (the American Toad, Bufo americanus) is known from Michigan. Frogs and turtle fossils are not known until later in the Pleistocene. Some very doubtful records of Pleistocene amphibians and especially reptiles occur in the literature (e.g., Dorr and Eschman 1970; Wilson 1967). These records have often been reported only as “from lake sediments” or from “beneath muck” or “beneath peat.” Most of these are probably Holocene and will be included in the Holocene accounts to follow. I have used the following procedure (published in Holman 1995a, 174) to recognize Pleistocene fossils in Michigan and the Great Lakes basin. A bone should meet at least one of the following three criteria: 1. It should be at least 10,000 radiocarbon years old or associated with some object that is 10,000 radiocarbon years old. 2. It should be in stratigraphic context with an extinct Pleistocene vertebrate such as a mastodont or a mammoth. 3. It should occur beneath (or in) sediments of known Pleistocene age.

Michigan’s Pleistocene Herpetofauna

Only two anurans, a frog and a toad, are presently recognized in the Pleistocene of Michigan. Both still occur in Michigan and are cold-tolerant species, one of which presently ranges northward to boreal areas and another that presently occurs in boreal areas as well as arctic tundra.

The Pleistocene began 1.8 Ma BP and ended 10 ka BP at the beginning of the Holocene (Palmer and Geissman 1999). The 1.8 Ma BP date is a bit arguable to some scientists, but the Pleistocene is now almost universally accepted to have ended about 10,000 radiocarbon years ago. The ending of the Pleistocene is based on the last verifiable dates of the existence of members of the mammalian megafauna, which consisted of very large, nowextinct mammals, including mastodonts and mammoths (Mead and Meltzer 1984; Meltzer and Mead 1983).

Anurans

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The Amphibians and Reptiles of Michigan

Family Bufonidae Bufo americanus Holbrook 1936 American Toad Site Meskill Road Site, 3.2 km (1.98 miles) WSW of Columbus, St. Clair County, Michigan, in sec. 16, T 5 N, R 15 E. The fossil was recovered by Fred Orzel from a water well at 22.9 m (75.1 ft.) below the surface in a sand layer beneath glacial clay and silt. Material One Bufo americanus complete right ilium (Michigan State University Museum, Vertebrate Paleontology collection, specimen no. 1074 [MSUVP 1074]).

FIG. 102. Right ilium of an American Toad (Bufo americanus) from the Late Wisconsinan Meskill Road Water Well Site, St. Clair County, Michigan. North American toads (Bufo) lack the ilial crest or blade on the ilial shaft (see fig. 98) found on true frogs (Rana). Illustration by Teresa Petersen.

Remarks I identified this fossil ilium (see fig. 102) on the basis of characters that were published in a journal article (see Holman 1967). The sand layer that contained the fossil American Toad was determined to be derived from Lake Whittlesey (see Dorr and Eschman 1970, 170, fig. 8-6), thus the bone age is estimated to be somewhat more than 13 ka BP but less than 13.8 ka BP. The vegetation in Michigan during this interval ranged from tundra to some boreal assemblages (see Kapp 1999, 42–47). Today, American Toads extend northward to boreal and arctic tundra areas in eastern Labrador and around the border of James Bay in Ontario, Canada (see Kendeigh 1961, 279, fig. 20-5; Logier and Toner 1961, 31, map 25; Conant and Collins 1998, 514, map), where they are presently considered to be the Eastern American Toad subspecies (Bufo americanus americanus), the same form that presently occurs in Michigan (Crother 2008). I consider

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American Toads to be primary postglacial reentrant taxa (Holman 2004). In other words, they were among the first herpetological taxa to reinvade Michigan after the last withdrawal of the Pleistocene ice.

Family Ranidae Rana clamitans Latreille 1901 Green Frog Site Shelton Mastodont Site, located on Seymour Lake Road between Oxford and Ortonville, in Brandon Township, Oakland County, in southeastern Michigan, in the SE¼ SE¼ sec. 26, T 5 N, R 9 E. The site lies in a low meadow just west of the Paint Creek tributary of the Clinton River (Shoshani et al. 1989). Nine radiocarbon dates indicate the site of the principal bone-bearing strata range from 12,320 ± 110 radiocarbon years to 11,740 ± 175 radiocarbon years before the present, which corresponds to the Twocreekan substage of the late Wisconsinan glaciation. Plant remains at the site associated with the fossil vertebrates indicate the presence of a forest dominated by conifers, mostly spruce. Material A right scapula (V33/81) and a left ilium (V187/855) of Rana clamitans were found. The provenance of the two specimen numbers and the institution where the fossils are deposited were not given by the authors (DeFauw and Shoshani 1991). Remarks R. O. Kapp indicated the vegetation in the area of the Shelton site during the Twocreekan substage of the Pleistocene would be composed of boreal forest (1999, 46, map). Today, Rana clamitans melanota (Northern Green Frog), the Michigan subspecies, extends northward to the boreal areas of northern Labrador, Canada (see Conant and Collins 1998, 560, map). Green Frogs are considered to be primary postglacial reentrant taxa in Michigan (Holman 2004).

Turtles Since the time I published that all of Michigan’s “Pleistocene” reptiles were considered to be either invalid or highly suspect (Holman 1988), the subsequent recovery of Painted Turtle (Chrysemys picta) remains

3. Quaternary Remains of Michigan Amphibians and Reptiles

directly associated with a mastodont (Mammut americanum) by Daniel C. Fisher became the first certain occurrence of a Pleistocene reptile in Michigan (Holman and Fisher 1993). In addition, a Spiny Softshell (Apalone spinifera) turtle femur was found not in direct association with but apparently in the same radiocarbon-dated Pleistocene paleosoil that was topographically associated with another mastodont (Holman and Fisher 1993).

Family Emydidae Chrysemys picta (Schneider 1783) Painted Turtle Site New Hudson Mastodont Site, Lyon Township, sec. 8, T 1 N, R 7 E, Oakland County, Michigan. These Painted Turtle bones (Holman and Fisher 1993) were directly associated with mastodont (Mammut americanum) remains, which included skull fragments, scapular (shoulder blade) fragments, ribs, and vertebrae (University of Michigan Museum of Paleontology, specimen no. 57885 [UMMP 57885]). These elements were collected by Daniel C. Fisher and his crew. The mastodont bones were taken

FIG. 103. Two plastral bones in ventral view of a Painted Turtle (Chrysemys picta) from the Late Wisconsinan New Hudson Mastodont Site, Oakland County, Michigan. Upper: right hypoplastron with annual growth rings. Lower: left hypoplastron. Illustration by Teresa Petersen.

from a sandbar that had been subsequently covered with about two meters (6.56 ft.) of peat. Fisher (1984) showed evidence that the mastodont was butchered by Paleo-Indians, but the turtle bones did not show evidence of human processing. Material Two lower shell bones (see fig. 103), a right hypoplastron (UMMP 52869) and a left hypoplastron (UMMP 52870), of Chrysemys picta. Remarks As noted in the modern species account, Painted Turtles are cold-tolerant animals that range into boreal habitats today across North America (Stebbins 2003). I have considered Painted Turtles to be primary postglacial reentrant taxa in Michigan (Holman 2004). Interesting paleoecological information was provided by the two turtle bones. It is well known that counting growth lines (“annuli”) visible on the plastral bones can allow an estimate of the minimum age of individual Painted Turtles (see Gibbons 1967; Ernst 1971; Wilbur 1975). The fossil hypoplastron (UMMP 52869) had eight such growth lines on the bottom surface of its plastron; thus, the animal was at least eight years old when it died. This bone is identical in size to a modern C. picta (Michigan State University Museum no. 1109) with a plastron length of 103 mm (4.1 in.). Based on age and size data presented by Gibbons (1967) for C. picta in Michigan, the fossil probably represents a male. Noteworthy is the fact that in three modern populations of C. picta in southern Michigan, the largest males were from a population that inhabited an enriched and polluted stretch of the Kalamazoo River, whereas the smallest males were from the “natural” Sheriff ’s Marsh population at the Kellogg Biological Station (Gibbons 1967). The turtle represented by the fossil hypoplastron more closely matches the Kalamazoo River population than the Sheriff Marsh population in terms of age and size (see Holman and Fisher 1993, figs. 3 and 4). A larger individual represented by hyoplastron UMMP 52870 is about 24 percent larger than a modern C. picta (MSU 3306) with a plastral length of 132 mm (5.2 in.). Projection would indicate that the fossil was a large female with a plastral length of about 160 mm (6.3 in.).

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The Amphibians and Reptiles of Michigan

Turtles are very important indicators of summer climates. The critical time in the life cycle of northern hemisphere turtles is the number of warm days in the summer necessary for the incubation of their eggs (Graham et al. 1983). A mean July temperature that exceeds 18ºC (64.4ºF) seems to be necessary for the European Pond Turtle (Emys orbicularis) to reproduce in Europe (Stuart 1979). The absence of modern European Pond Turtles in Britain as well as the repeated failure to establish the Painted Turtle (C. picta) in Britain may be because of too few warm, sunny days for successful reproduction. This modern situation would indicate that the summer climate during New Hudson mastodont times at least had a sufficient number of warm days to maintain Painted Turtle populations.

Family Trionychidae Apalone spinifera (Lesueur 1927) Spiny Softshell Turtle Site Heisler Mastodont Site, Clarence Township, sec. 14, T 1 S, R 4 W , Calhoun County, Michigan. The Heisler Mastodont Site was discovered by James and Lester Heisler in the summer of 1984. In November 1984, I visited the site and found several fragmentary mastodont bones that came from a shelly marl below a peaty layer that was represented at the surface by a “black soil.” Later, wood from the site yielded a radiocarbon date of 11,160 ± 110 years. Daniel C. Fisher continued digging the Heisler Site and found additional mastodont bones, including a skull. Based on several lines of evidence, he interpreted the site as a location where humans had butchered and stored meat (Fisher 1989). Material An Apalone spinifera right femur (UMMP 52871). Remarks Bearss and Kapp (1987) studied the fossil vegetation at the Heisler Site, and on the basis of pollen analysis determined that spruce forest dominated the area when the mastodont and Spiny Softshell lived. They suggested this location was formerly a pond surrounded by spruce and cedar. Later, in the layer of peat deposition, spruce pollen declined in abundance and that of pine and oak increased significantly. A radiocarbon date of 10,740 ±

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FIG. 104. Right femur, about 10,000 years old, of a Spiny Softshell (Apalone spinifera) turtle taken near the Heisler Mastodont Site near Lansing, Michigan. Illustration by Jane Kaminski.

300 years was yielded by the peat. The Spiny Softshell femur was found approximately 200 m (656 ft.) to the west of the mastodont at the surface of the plow zone in “black soil” identical to that which occurred above the mastodont bones. The turtle bone was in the center of a series of depressions that adjoined those in which the mastodont remains occurred. It seems reasonable to correlate the peat deposition of the turtle femur depression with the peat deposition in which the mastodont occurred. The Spiny Softshell that lives in Michigan today is grouped with the hypothetical secondary postglacial reentrant taxa (Holman 1992), thus the fossil Spiny Softshell would have been able to adjust to climatic areas that supported a mixed conifer and broadleaf vegetation. This would be in line with the stratigraphic association of the turtle femur with the peat deposit, and with the finding of Bearss and Kapp that the peat at the site was characterized by an increase in pine and oak pollen. Given its radiocarbon date, the Spiny Softshell could represent one of the earliest Pleistocene occurrences of a reptile that followed the regional decline of spruce in the area.

3. Quaternary Remains of Michigan Amphibians and Reptiles

Michigan’s Holocene Herpetofauna The Holocene Epoch began about 10 ka BP and was marked by the absence of many large terrestrial mammals, such as mastodonts and mammoths that became extinct at the end of the Pleistocene (e.g., Holman 2001a; Meltzer and Mead 1983). The extinction of the large mammals by 10 ka BP is the most widely used way to attempt to pinpoint the end of the Pleistocene and the beginning of the Holocene. But R. O. Kapp (1999, 51) looked at the situation through the eyes of a paleobotanist (student of fossil plants) and pointed out that “the paleoecological changes that occurred between 10,500 and 9500 BP were of such revolutionary proportions that these are the primary basis for defining the boundary between the late-glacial and the postglacial or Holocene.” Holocene climates exhibited a warming trend in North America until about 5,000 years ago (Matsch 1976). Between about 7,000 and 5,000 years ago the warming trend peaked during a time span called the Hypsithermal Interval. At this time the world temperature is thought to have averaged about 2 to 3ºC warmer than it is today. Since the Hypsithermal Interval, the earth has generally been cooler and moister. In fact, this trend has been referred to as a “neoglaciation,” based on the expansion of mountain glaciers in North America. Michigan had a long cooling period that began 1,200 years ago and reached a peak in the 1700s. The climate in Michigan then warmed again from about 1750 to 1850 (Bernabo 1981; Kapp 1999). Events in the Holocene were very important factors in the present distribution of amphibian and reptile species.

Anurans As in the Pleistocene, only two anurans, a frog and a toad, are presently recognized in the Holocene of Michigan. Both of these animals still occur in Michigan and are cold-tolerant species that range northward to boreal and arctic tundra areas today.

Family Bufonidae Bufo americanus Holbrook 1936 American Toad Site Dolomitic Fissure 1 Site, Mackinac County, Michigan, about 2 miles NE of East Lake in the Hiawatha

National Forest, in the SE corner of sec. 34, T 44 N, R 4 W (Holman et al. 2003). Several fissures in the area were investigated, but a single fissure designated “Fissure 1” was studied. At present the area surrounding Fissure 1 is primarily beech-maple forest. The presettlement vegetation, however, was probably white pine–hemlock– maple (Comer et al. 1998). A radiocarbon date from charcoal collected at Fissure 1 (Beta 169996) was 240 ± 40 radiocarbon years before the present (1692–1772). Calibration of this date indicates the probability is about 66 percent that the date is correct. Material Bones from the skull and hip girdle, including two sacra and two ilia of Bufo americanus (MSUVP 2052). Remarks The ilium is probably the most diagnostic skeletal element for the identification of fossil anuran species. Holman (2003) gave ilial criteria for the separation of Bufo americanus from other species of the genus. The Fissure 1 ilia represent a juvenile toad with a snout-tovent length of about 25 mm (.98 in.). The American Toad occurred with at least seven species of small mammals. All of these presently occur in Mackinac County with the exception of the Northern Bog Lemming (Synaptomys cf. Synaptomys borealis). If the identification of the Northern Bog Lemming is correct, the temperature at the time of the deposition of the bones was probably cooler than at present, and a greater percentage of coniferous trees were likely growing in the area. This situation would be in line with the authors’ suggestion that the findings in Fissure 1 represent the Little Ice Age period in Michigan. Modern Bufo americanus ranges into the boreal and arctic tundra areas in Canada and occurs in the Mackinac County area today.

Family Hylidae Pseudacris crucifer (Wied-Neuwied 1938) Spring Peeper Site The Spring Peeper was also identified at the Dolomitic Fissure 1 Site, Mackinac County, Michigan (Holman et al. 2003).

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Material A Pseudacris crucifer right ilium (MSUVP 2053). Remarks Fossil Frogs and Toads of North America (Holman 2003) gives ilial characters for the identification of this species as a fossil. The Spring Peeper is widespread in boreal areas of Canada and reaches the arctic tundra along the border of James Bay in Ontario (Conant and Collins 1998, 541, map). I have observed that this species occurs in the area of Fissure 1 today.

Reptiles All the reptiles that have been recognized from the Holocene of Michigan are turtles. Some of these were previously considered to represent the Pleistocene.

Family Chelydridae Chelydra serpentina serpentina (Linnaeus 1758) Eastern Snapping Turtle Sites and Material The Snapping Turtle was reported on the basis of two occurrences. Two portions of a carapace (upper shell) (UMMP 33772) were discovered in a drainage ditch in Millington Township, Tuscola County, in the SSE corner of the NW¼ NE¼, sec. 30, T 10 N, R 8 E (Wilson 1967). It was reported that the shell fragments were on “beach sand” at the base of a peat deposit. At another site, five portions of a Snapping Turtle shell (UMMP 44442) were taken from a layer of peat at a depth of 15 feet (457.2 cm) at a location “halfway between Thirteen and Fourteen Mile Roads,” Farmington Township, in Oakland County, Michigan (Wilson 1967). Remarks Relative to the Tuscola County site, it is difficult to determine from the meager description that was given whether the bones were found in the peat layer or the sand layer, and whether the sand was a stratigraphically dated “beach sand.” Moreover, regarding both of these records, exceedingly thick peat deposits in Michigan can be younger than 7,000 radiocarbon years old (Holman 1990). Therefore, because these Snapping Turtle elements do not exhibit any of the three criteria used here for establishing a Pleistocene age for excavated remains (see page 215), I suggest they belong in the Holocene, possibly somewhat

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near the middle of the epoch. The farthest northward this turtle has been recorded is at the Berens River, Manitoba, and in the Maritimes (Logier and Toner 1961).

Family Emydidae Chrysemys picta (Schneider 1783) Painted Turtle Sites The Harper Site in Shiawassee County, northeast of Lansing, is the most important reptile Holocene site in Michigan because of its calibrated radiocarbon date (Stuiver and Reimer 2003) and because four species of turtles (one of which is Chrysemys picta) have been identified from the deposit. The Harper Site is on the property of Robert and Doris Harper of Shaftsburg in the NW¼, sec. 10, T 5 N, R 1 E, Shiawassee County. The bones were exposed during the commercial excavation of peat by the Anderson Company of Shaftsburg. The sequence of strata (identifiable layers) from top to bottom at the Harper Site in the restricted area where the turtles were found is as follows (Holman 1990): Peat (commercial grade) 0–2.43 m Gray, shelly marl (fossil zone) 2.44–4.17 m Bluish-gray clay 4.18–4.77 m Glacial sand and gravel 4.78 m downward The entire Holocene vertebrate assemblage at the Harper Site consisted of the remains of nine elk (wapiti), one white-tailed deer, a beaver (represented by beaver-gnawed wood), a mallard duck, four turtles, and a large-mouth bass. Wood associated with one of the elk skeletons yielded a radiocarbon date of 5,840 ± 80 years before the present. Recently that date has been calibrated by Stuiver and Reimer (2003), the new work indicating a date that occurred somewhere between 6,850 and 6,647 radiocarbon years ago. Ronald Kapp (1999) analyzed a pollen sample from the site and found that deciduous trees accounted for 73 percent of the sample. Prominent tree species were maple, 2.2 percent; oaks, 46.2 percent; elms, 14.1 percent; birches, 1.8 percent; and hophornbeams and hornbeams, 6.2 percent. The pieces of wood, coniferous cones, seeds, plant fiber, and mollusk fauna (countless thousands of small shells) as well as the vertebrate bones probably accumulated as layers of organic debris on the bottom

3. Quaternary Remains of Michigan Amphibians and Reptiles

of a well-oxygenated small lake as the fossiliferous shelly marl layer was formed. As the lake filled in, the thick peat layer accumulated. The elk and the white-tailed deer may have drowned as the lake filled in, perhaps after becoming mired in the mucky sediments. Modern white-tailed deer have been seen drowning in such situations today (Dr. J. C. Ferguson, pers. comm., 1989). No evidence of their being butchered by humans is apparent.

Material A Chrysemys picta right hypoplastron, two fragmentary peripherals (short bones bordering the upper shell), and a shell fragment (MSUVP 1262). Remarks Needless to say, the Painted Turtle was probably the most abundant turtle in this shallow lake community, again inhabiting an area that had been buried under a mile or so of glacial ice a few thousand years earlier. Pushed out of Michigan then, this turtle plodded north from pond to pond and home again. The Painted Turtles at the Harper Site would have lived in the parts of the lake that had abundant aquatic vegetation. The Painted Turtle is also known from the undated Farmington Township site in Oakland County, Michigan, from a layer of peat at a depth of 15 feet (457.2 cm). This is the same site that yielded the Snapping Turtle remains just described. The material consisted of two fragments of a carapace (UMMP 44443).

Clemmys guttata (Schneider 1792) Spotted Turtle Site Only one record of the Spotted Turtle is known from the Holocene in Michigan, and that record is from the Harper Site in Shiawassee County. Material Right Clemmys guttata epiplastron (the anterior-most paired bones of the plastron) (MSUVP 1263).

FIG. 105. A Painted Turtle (Chrysemys picta) (top) and an Eastern Musk Turtle (Sternotherus odoratus) (bottom) bask in a pond while an elk (wapiti) looks on in a scene that re-creates the possible appearance of the midHolocene Harper Site near Lansing, Michigan. Illustration by Teresa Petersen.

The turtle fauna, pollen studies, and radiocarbon date indicate a much milder climate in southern Michigan than had occurred a few thousand years before at the end of the Pleistocene. Judging from the four species of turtles that were present—Painted Turtle, Spotted Turtle, Blanding’s Turtle, and especially an Eastern Musk Turtle—I would boldly suggest that most of the modern herpetofauna was in place in the southern part of the Lower Peninsula during the Harper Site time.

Remarks This Spotted Turtle would have lived in the shallowest, most marshy areas of the Harper Site Holocene community.

Emydoidea blandingii (Holbrook 1938) Blanding’s Turtle Site The Blanding’s Turtle is also known in the Holocene of Michigan only from the Harper Site. Material A partial plastron consisting of a left epiplastron, entoplastron, a left and right hyoplastron, and a right hypoplastron of Emydoidea blandingii (MSUVP 1264).

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Remarks In the Harper Site community, Blanding’s Turtle would have lived in habitats that are somewhat intermediate between those of the Painted Turtle and the Spotted Turtle.

Graptemys sp. Agassiz 1957 Specifically Undetermined Map Turtle

Remarks This small, bottom-crawling turtle species would likely have been found foraging for food along the submerged marl of the Harper Site.

Site Mouth of the Saginaw River in sec. 2, T 14 N, R 5 E, Bay County, Michigan (Wilson and Zug 1966; Wilson 1967).

Family Trionychidae Apalone spinifera (Lesueur 1927) Spiny Softshell

Material This record is based on a Graptemys right hypoplastron that was dredged from the mouth of the Saginaw River. Remarks Wilson and Zug (1966) originally identified this hypoplastron as Graptemys pseudogeographica, a species that presently occurs south of Michigan (Conant and Collins 1998, 171, map). They stated that radiocarbon dating of the hypoplastron was not attempted but that on the basis of the stratigraphic position, ecological requirements, climatic trends following glaciation, and its present relict distribution, the range of G. pseudogeographica probably extended into Michigan 4,000 to 6,000 years ago. I found that the characters used by Wilson and Zug were individually variable in both the present-day Michigan Map Turtle species Graptemys geographica and the more southern species G. pseudogeographica (Holman 1988). I would suggest here again that the hypoplastron be designated merely as a Graptemys species (a specifically undetermined Map Turtle). Graptemys pseudogeographica as known to Wilson and Zug is now considered a complex group of species and possibly subspecies (e.g., Minton 2001). This situation contributes greatly to the difficulty of identifying fossil Map Turtles.

Family Kinosternidae Sternotherus odoratus (Latreille 1901) Eastern Musk Turtle Site This Eastern Musk Turtle is the fourth species of turtle known from the Harper Site.

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Material A Sternotherus odoratus eighth right peripheral bone (MSUVP 1261).

Site Fenton Lake Locality of the NE¼ sec. 14, T 5 N, R 6 E of Genesee County (Wilson 1967). Material and Remarks Bones of this turtle were taken between a peat zone and a calcareous clay zone at the Fenton Lake Locality. The fact that specimens of bone occur between marl and peat does not imply a Pleistocene age for these specimens. I believe it is better to consider this an undesignated Holocene record. The scientific name was originally cited as “Trionyx cf. T. spinifer” by Wilson (1967).

Herpetofauna of Michigan Archaeological Sites All of the herpetological species yielded from archaeological sites in Michigan are from the Holocene. These bones are usually identified by archaeological specialists known as zooarchaeologists rather than by vertebrate paleontologists. However, the two groups often cooperate with each other in the identification of vertebrates from archaeological sites and by sharing information about these animals. From the standpoint of the herpetologist, Michigan amphibian and reptile remains from archaeological sites supply additional information about the herpetological life of the Holocene and have posed some interesting questions about changes in the distribution of amphibians and reptiles in Michigan in both time and space. From the standpoint of the archaeologist, they provide information about the place of ancient people in their environment and how they lived in it. These Holocene records of amphibians and reptiles may be used to answer questions about the environment itself, including habitats in the

3. Quaternary Remains of Michigan Amphibians and Reptiles

vicinity of a site, and about how animals were used in the daily lives of people who lived there. Because amphibians and reptiles are not available year round, they provide clues about the seasons during which a site might have been occupied. Such sites were normally used only temporarily by people who moved through a region to get food. The condition of the bone itself is also important in determining how it was used. For example, white or blue bone indicates it has been in a fire, with the implication that the animal was probably cooked and eaten. Many times burned bones occur in tiny fragments, indicating they were broken up and cooked along with meat and other ingredients in dishes similar to stews. Cut marks on bone may contribute knowledge about the way the animal was prepared for eating or about how bones were made into tools or religious items. Again, with regard to turtles, indications of the removal of parts of a carapace may be correlated with the manufacture of a bowl or some other artifact. Although the number of identifiable specimens provides a rough idea of the relative abundance of different animals, determining the minimum number of individuals present is more useful. Two right turtle femora (upper leg bones) indicate that at least two individuals were present, whereas twenty fragments could represent one turtle or twenty; thus the two turtle femora are more significant than the twenty fragments. Turtles in particular were sources of food and their shells were also sometimes fashioned into bowls or rattles. Unique carved turtle carapaces found as holders of grave foods in the Norton Mounds in Grand Rapids are indications that for these people at least, turtles were significant in their ritual and spiritual life (Griffin et al. 1970). Vertebrate bones from Michigan archaeological sites must be placed in a context of time and space, for the relationships between people and their environment changed throughout the nearly 12,000 years people have lived in the state. Assessing time at archaeological sites may include radiocarbon dating or knowing the cultural period to which the artifacts in the site belong, or both. The archaeological sequence of cultural periods to follow will be used to indicate time in the amphibian and reptile-bearing archaeological sites listed in the pages to follow. The numbers below refer to the beginning of the cultural period. Two ways of presenting these time frames

are used in the literature. I will use the one on the left (BP represents years before present). 350 BP—Historic 1,600 BP—Late Woodland 2,300 BP—Middle Woodland 3,000 BP—Early Woodland 5,000 BP—Late Archaic 8,000 BP—Middle Archaic 10,000 BP—Early Archaic 12,000 BP—Paleo-Indian

AD 1650—Historic AD 400—Late Woodland 300 BC—Middle Woodland 1000 BC—Early Woodland 3000 BC—Late Archaic 6000 BC—Middle Archaic 8000 BC—Early Archaic 10,000 BC—Paleo-Indian

I have not included the Late Mississippian period in the list because it is a cultural unit within the time frame of the Late Woodland in Michigan.

Anurans As in the Pleistocene and Holocene paleontology sites, only two anurans—a frog and a toad—are presently known at the specific level from Michigan archaeological sites. Both of these species are very common in the state today. The lists of numbers in parentheses to the right of each site name are Michigan State Site Numbers that are kept in the office of the state archaeologist in Lansing. These numbers pinpoint the location of archaeological sites in the state. Sometimes only these numbers (rather than both site names and numbers) are used in published archaeological site reports.

Family Bufonidae Bufo americanus Holbrook 1936 American Toad Site 1. Cassasa Site (20SA1021), near St. Charles, Saginaw County, Michigan (Smith and Chiles-Artymko 1995). Age Middle Woodland. Remarks As far as I am aware, these are the only Bufo in the archaeological record in Michigan that have been identified to the species level. This species occurs in the modern fauna of Sagninaw County today (Holman 2004).

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Site 2. Trombly House (20BY70), Bay City, Bay County, Michigan (Martin and Colburn 1989).

Age This Bullfrog was found in both the Middle and Late Woodland portions of the Cassasa Site.

Age Late Woodland or 1830s Historic.

Remarks Individuals of this frog species were certainly large enough for eating purposes by the people of the times. As far as I am aware, Rana catesbeiana is the only Rana that has been identified to the specific level in archaeological studies in Michigan. Oddly, the American Bullfrog has not been verified in the modern herpetofauna of Saginaw County (Holman 2004) although this frog is the largest anuran in the state and has a characteristic loud voice. I do not doubt that this frog presently occurs in Saginaw County.

Remarks The American Toad has been recorded in the modern fauna of Bay County (Holman 2004).

Bufo sp. Toad Site 1. Slavic Site (20GR221), near the Maple River, Gratiot County, Michigan (Martin and Kolis 1996). Age Late Woodland. Remarks The material found at this site could represent either B. americanus or B. fowleri, but the probability is that it is the former, as B. fowleri has not been recorded in the modern fauna of Gratiot County and B. americanus has (Holman 2004). Site 2. Wymer West Knoll Site (20BE132), Berrien County, Michigan (Martin and Richmond 2001). Age Late Woodland, Late Mississippian cultural unit. Remarks This toad could be either B. americanus or B. fowleri; both have been recorded in the modern fauna of Berrien County (Holman 2004).

Family Ranidae Rana catesbeiana Shaw 1902 American Bullfrog Site 1. Cassasa Site (20SA1021), Saginaw County, near St. Charles, Michigan (Smith and Chiles-Artymko 1995).

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Site 2. Elba Township Site (20LP98), Lapeer County, Michigan (Martin 1979). Age Late Middle to early Late Woodland. Remarks These frog bones were unmodified by humans. This species has been recorded from Lapeer County in modern times (Holman 2004).

Rana sp. True Frog Site 1. O’Neil Site (20CX18), near the city of Charlevoix, Charlevoix County, Michigan (Lovis 1973). Age Late Woodland. Remarks This material could represent one of several Rana species that are presently found in Charlevoix County. Site 2. Stadelmeyer Site (20SA195) near the city of Saginaw, Saginaw County, Michigan (Bigony 1970).

3. Quaternary Remains of Michigan Amphibians and Reptiles

Age Late Woodland. Remarks This material could represent one of several species of Rana species that undoubtedly occurred in Saginaw County during Late Woodland times. Site 3. Wymer West Knoll Site (20BE132), Berrien County, Michigan (Martin and Richmond 2001). Age Late Woodland, Late Mississippian cultural unit. Remarks This unidentified species of True Frog may represent an intrusive species at the site (Martin and Richmond 2001).

Reptiles As might be expected, turtles are by far the most numerous reptiles found in Michigan archaeological sites. Large species, such as Snapping Turtles and Spiny Softshells, were clearly important food items in the diet of Native Americans. Somewhat smaller species, such as Blanding’s Turtles, Map Turtles, and Red-eared Sliders, were probably eaten occasionally. The carapaces of Blanding’s Turtles, Box Turtles, and Painted Turtles were used as bowls or for ceremonial objects. I have no idea whether the very small, smelly Eastern Musk Turtle was used for anything.

Family Chelydridae Chelydra serpentina (Linnaeus 1758) Snapping Turtle Site 1. Bear Creek Site (20SA1043), St. Charles Township, Saginaw County, Michigan (Smith in Branstner and Hambacher 1994). Age Middle Archaic through early Late Woodland.

Site 2. Rock Hearth Site (20BE306), Oronoko Township, St. Joseph River, Berrien County, Michigan (Garland et al. 1990). Age Late Archaic. Remarks This species has been recorded in the modern fauna of Berrien County (Holman 2004). Site 3. Schmidt Site (205A192), near Bridgeport, Saginaw County, Michigan (Cleland 1966; Adler 1968). Age Late Archaic. Remarks This species has been recorded in the modern fauna of Saginaw County (Holman 2004). Site 4. Vogelaar Site (205A291), near St. Charles, Saginaw County, Michigan (Smith and Cooper 1995). Age Late Archaic to early Late Woodland. Remarks This species has been recorded in the modern fauna of Saginaw County (Holman 2004). Site 5. Weber I Site (20SA581), Frankenmuth Township, Saginaw County, Michigan (Smith and Egan 1990). Age Late Archaic. Remarks This species occurs in the modern fauna of Saginaw County (Holman 2004).

Remarks This species has been recorded in the modern fauna of Saginaw County (Holman 2004).

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Site 6. Kantzler Site (20BY30), Bay City, Bay County, Michigan (Crumley 1973). Age Early to Late Woodland and Historic. Remarks Oddly, the occurrence of this species has not been verified in the modern fauna of Bay County (Holman 2004), although it undoubtedly occurs there. Site 7. Carp River Site (FS-09-10-05-322) near St. Martin Bay, Mackinac County, Michigan (Dunham et al. 1993). Age Middle Woodland. Remarks The Snapping Turtle has been recorded in the modern fauna of Mackinac County (Holman 2004). Site 8. Marquette Viaduct Site (20BY28), Bay City, Bay County, Michigan (Lovis et al. 1996). Age Middle Woodland. Remarks The occurrence of the Snapping Turtle has not been verified in the modern fauna of Bay County, but it undoubtedly occurs there (Holman 2004). Site 9. Schultz Site (20SA2), at the confluence of the Tittabawassee and Saginaw Rivers, Saginaw County, Michigan (Cleland 1966; Halsey 1966; Adler 1968; Shipman 2004). Age Middle Woodland. Remarks This species has been recorded in the modern fauna of Saginaw County (Holman 2004).

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Site 10. Cassasa Site (20SA1021), near St. Charles, Saginaw County, Michigan (Smith and Chiles-Artymko 1995). Age Late Woodland. Remarks This turtle has been recorded in the modern fauna of Saginaw County (Holman 2004). Site 11. Juntunen Site (20MK1), Bois Blanc Island, Mackinac County, Michigan (Cleland 1966; Adler 1968). Age Late Woodland. Remarks This turtle has not been recorded in the modern fauna of Bois Blanc Island (Cleland 1966; Adler 1968; Holman 2004). Site 12. Slavic Site (20GR221), near the Maple River, Gratiot County, Michigan (Martin and Kolis 1996). Age Late Woodland. Remarks This species has been recorded in the modern fauna of Gratiot County (Holman 2004). Site 13. Stadelmeyer Site (20SA195) near the city of Saginaw, Saginaw County, Michigan (Bigony 1970). Age Late Woodland. Remarks This species has been recorded in the modern fauna of Saginaw County (Holman 2004).

3. Quaternary Remains of Michigan Amphibians and Reptiles

Site 14. Trombley House (20BY70), Bay City, Bay County, Michigan (Martin and Colburn 1989). Age Late Woodland or 1830s Historic. Remarks This species has not been recorded in the modern fauna of Bay County, but it undoubtedly occurs there (Holman 2004).

Remarks This species occurs in the modern fauna of Saginaw County (Holman 2004). Site 2. Bear Creek Site (20SA1043), St. Charles Township, Saginaw County, Michigan (Smith in Branstner and Hambacher 1994). Age Middle Archaic to early Late Woodland.

Site 15. Moccasin Bluff (20BE8), north of Buchanan, Berrien County, Michigan (Cleland 1966; Adler 1968; Betteral and Smith 1973).

Remarks This species has been recorded in the modern fauna of Saginaw County (Holman 2004).

Age Late Woodland, Late Mississippian cultural unit.

Site 3. Bay City (20BY79 and 20BY77), Bay County, Michigan (Franz 1993).

Remarks This species has been recorded in the modern fauna of Berrien County (Holman 2004). Site 16. Wymer West Knoll Site (20BE132), Berrien County, Michigan (Martin and Richmond 2001). Age Late Woodland, Late Mississippian cultural unit. Remarks The turtles in this fauna were unmodified by humans. This species has been recorded from the modern fauna of Berrien County (Holman 2004).

Family Emydidae Chrysemys picta (Schneider 1783) Painted Turtle Site 1. Weber I (20SA581), Frankenmuth Township, Saginaw County, Michigan (B. A. Smith 1989). Age Middle Archaic.

Age Site 20BY79 has both Late Archaic and Late Woodland components, and remains of Chrysemys picta occur in both of them. Site 20BY77 has Chrysemys picta in the Late Woodland. Remarks Chrysemys picta has not been recorded in the modern fauna of Bay County (Holman 2004), but there is no doubt that this species occurs there today. Site 4. Rock Hearth Site (20BE306), St. Joseph River, Oronoco Township, Berrien County, Michigan (Garland et al. 1990) Age Late Archaic. Remarks This species has been recorded in the modern fauna of Berrien County (Holman 2004). Site 5. Marquette Viaduct Site (20BY28), Bay City, Bay County, Michigan (Lovis et al. 1996).

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Age This site consists of both Middle Woodland and Late Woodland components with Painted Turtle material found in both of them. Remarks The Painted Turtle has not been recorded in the modern fauna of Bay County, but this very common Michigan species undoubtedly occurs there at present. Site 6. Cassasa Site (20SA1021), near St. Charles, Saginaw County, Michigan (Smith and Chiles-Artymko 1995). Age Middle and Late Woodland components with Chrysemys picta remains occurring in both of them. Remarks The Painted Turtle has been recorded in the modern fauna of Saginaw County (Holman 2004). Site 7. Schultz Site (20SA2), at the confluence of the Tittabawassee and Shiawassee Rivers, Saginaw County, Michigan (Cleland 1966; Adler 1968; Shipman 2004). Age Middle Woodland. Remarks This species has been recorded in the modern fauna of Saginaw County (Holman 2004). Site 8. Caseville Airport Site (20HU164), near Caseville and Sand Point, Huron County, Michigan (Holman et al. 1988).

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Site 9. Juntunen Site (20MK1), Bois Blanc Island, Mackinac County, Michigan (Cleland 1966; Adler 1968). Age Late Woodland. Remarks This species has not been recorded in the modern fauna of Bois Blanc Island (Cleland 1966; Adler 1968; Holman 2004). Site 10. O’Neil Site (20CX18), near the city of Charlevoix, Charlevoix County, Michigan (Lovis 1973). Age Late Woodland. Remarks This turtle has been recorded in the modern fauna of Charlevoix County (Holman 2004). Site 11. Pine River Channel Site (20CX19), in the city of Charlevoix, Charlevoix County, Michigan (M. B. Holman 1978). Age Late Woodland. Remarks This species has been recorded in the modern fauna of Charlevoix County (Holman 2004). Site 12. Porter Creek South (20MN100), Manistee National Forest, Mason County, Michigan (B. A. Smith 1995).

Age Late Woodland.

Age Late Woodland.

Remarks This species has been recorded in the modern fauna of Huron County (Holman 2004).

Remarks This species has been recorded in the modern fauna of Mason County (Holman 2004).

3. Quaternary Remains of Michigan Amphibians and Reptiles

Site 13. Ranger Walker II (200A181), Manistee National Forest, Oceana County, Michigan (Smith in Branstner 1991). Age Late Woodland. Remarks The Painted Turtle has been recorded from the modern fauna of Oceana County (Holman 2004). Site 14. Spring Creek Site (20MU3), Egelston Township, Muskegon County, Michigan (Martin 1990). Age Late Woodland. Remarks This species has been recorded from the modern fauna of Muskegon County (Holman 2004). Site 15. Site FS 09-10-01-328, Hiawatha National Forest, Delta County, Michigan (Weir and Anderton 1991). Age Late Woodland. Remarks These Painted Turtle remains were modified by humans into bowls or rattles. The Painted Turtle has been recorded in the modern fauna of Delta County. Site 16. Trombley House (20BY70), Bay City, Bay County, Michigan (Martin and Colburn 1989). Age Late Woodland. Remarks This species has not been recorded in the modern fauna of Bay County, but it undoubtedly occurs there (Holman 2004).

Site 17. Wymer West Knoll Site (20BE132), Berrien County, Michigan (Martin and Richmond 2001). Age Late Woodland, Late Mississippian cultural unit. Remarks This species has been recorded in the modern fauna of Berrien County (Holman 2004).

Clemmys guttata (Schneider 1792) Spotted Turtle Site Schultz Site (20SA2), confluence of the Tittabawassee and Shiawassee Rivers in Saginaw County, Michigan (Adler 1968). Age Middle Woodland. Remarks This species has been recorded in the modern fauna of Saginaw County (Holman 2004).

Emydoidea blandingii (Holbrook 1938) Blanding’s Turtle Site 1. Bear Creek Site (20SA1043), St. Charles Township, Saginaw County, Michigan (Smith in Branstner and Hambacher 1994). Age Middle Archaic through early Late Woodland. Remarks This species has been recorded in the modern fauna of Saginaw County (Holman 2004). Site 2. Marquette Viaduct Site (20BY28), Bay City, Bay County, Michigan (Lovis et al. 1996). Age Middle Woodland component of this site.

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The Amphibians and Reptiles of Michigan

Remarks This species is recorded in the modern fauna of Bay County (Holman 2004).

Remarks This turtle has been recorded in the modern fauna of Saginaw County (Holman 2004).

Site 3. Norton Mound, Wyoming Township, Kent County, Michigan (Griffin et al. 1970; Halsey 1966).

Site 7. Juntunen Site (20MK1), Bois Blanc Island, Mackinac County, Michigan (Adler 1968).

Age Middle Woodland.

Age Late Woodland.

Remarks This species has been reported in the modern fauna of Kent County.

Remarks This species has not been recorded in the modern fauna of Bois Blanc Island (Cleland 1966; Adler 1968).

Site 4. Schultz Site (20SA2), at the confluence of the Tittabawassee and Shiawassee Rivers, Saginaw County, Michigan (Halsey 1966; Murray 1972; Shipman 2004).

Site 8. Cassasa Site (20SA1021), near St. Charles, Saginaw County, Michigan (Smith and Chiles-Artymko 1995).

Age Early and Middle Woodland components. Remarks This species has been recorded in the modern fauna of Saginaw County (Holman 2004). Site 5. Aldrich Site (20GR221), Gratiot County, Michigan (Martin and Kolis 1996). Age Late Woodland. Remarks This turtle has not been recorded in the modern fauna of Gratiot County, Michigan, but it no doubt occurs there (Holman 2004). Site 6. Bridgeport Township Site (20SA620), Bridgeport, Saginaw County, Michigan (Mudar 1990). Age Late Woodland.

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Age Late Woodland component of this site. Remarks This turtle has been recorded in the modern fauna of Saginaw County (Holman 2004). Site 9. Ranger Walker I (200A180) and II (200A181), Manistee National Forest, Oceana County, Michigan (Branstner 1991). Age Both sites I and II are Late Woodland. Remarks This species has been recorded from the modern fauna of Oceana County (Holman 2004). Site 10. Slavic Site (20GR221), near the Maple River, Gratiot County, Michigan (Martin and Kolis 1996). Age Late Woodland.

3. Quaternary Remains of Michigan Amphibians and Reptiles

Remarks This species has not been recorded in the modern fauna of Gratiot County, but it probably occurs there (Holman 2004). Site 11. Stadelmeyer Site (205SA195), near the city of Saginaw, Saginaw County, Michigan (Bigony 1970). Age Late Woodland. Remarks This species has been recorded in the modern fauna of Saginaw County (Holman 2004). Site 12. Kantzler Site (20BY30), Bay City, Bay County, Michigan (Crumley 1973).

Remarks Blanding’s Turtle has been recorded in the modern fauna of Berrien County (Holman 2004).

Glyptemys insculpta (LeConte 1930) Wood Turtle Site Juntunen Site (20MK1), Bois Blanc Island, Mackinac County, Michigan (Adler 1968). Age Late Woodland. Remarks This turtle has not been found in the modern fauna of Bois Blanc Island (Holman 2004).

Graptemys geographica (Lesueur 1917) Northern Map Turtle

Remarks This species has been recorded in the modern fauna of Bay County (Holman 2004).

Site 1. Schultz Site (20SA2), junction of the Tittabawasse and Shiawassee Rivers, Saginaw County, Michigan (Cleland 1966, Adler 1968). Age Middle Woodland.

Site 13. Trombley House (20BY70), Bay City, Bay County, Michigan (Martin and Colburn 1989).

Remarks This species has not been recorded in the modern fauna of Saginaw County but probably occurs there (Holman 2004).

Age Early to Late Woodland and Historic.

Age Late Woodland or 1830s Historic. Remarks This species has been recorded in the modern fauna of Bay County (Holman 2004). Site 14. Moccasin Bluff (20BE8), north of Buchanan, Berrien County, Michigan (Cleland 1966; Betteral and Smith 1973).

Site 2. Stadelmeyer Site (205SA195), near the city of Saginaw, Saginaw County, Michigan (Bigony 1970). Age Late Woodland. Remarks The Northern Map Turtle has not been recorded in the modern fauna of Saginaw County but probably occurs there (Holman 2004).

Age Late Woodland, Late Mississippian cultural unit.

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The Amphibians and Reptiles of Michigan

Site 3. Moccasin Bluff (20BE8), north of Buchanan, Berrien County, Michigan (Cleland 1966; Adler 1968; Betteral and Smith 1973). Age Late Woodland, Late Mississippian cultural unit. Remarks This species has not been recorded in the modern fauna of Berrien County but almost certainly occurs there at present (Holman 2004). Site 4. Wymer West Knoll Site (20BE132), Berrien County, Michigan (Martin and Richmond 2001). Age Late Woodland, Late Mississippian cultural unit. Remarks This species has not been recorded in the modern fauna of Berrien County but almost certainly occurs there at present (Holman 2004). Graptemys pseudogeographica, the False Map Turtle, has also been recorded from this site. It does not presently occur in Michigan today (see Conant and Collins 1998, 171, map) and is very difficult to distinguish from the Northern Map Turtle on the basis of shell elements (see discussion in Holman 1988). I suggest that the specimen assigned to G. pseudogeographica probably represents G. geographica.

Terrapene carolina (Linnaeus 1758) Eastern Box Turtle Site 1. Schultz Site (20SA2), at the junction of the Tittabawasse and Shiawasee Rivers, Saginaw County, Michigan (Cleland 1966; Halsey 1966; Adler 1968). Age Middle Woodland. Remarks This species has not been recorded in the modern fauna of Saginaw County, and the presence of its remains

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at the Schultz Site are thought to be from intertribal trading (Adler 1968; Holman 2001b, 2004). Site 2. Norton Mound Group (20KT1), Wyoming Township, Kent County, Michigan (Griffin et al. 1970). Age Middle Woodland. Remarks Two dishes made from the carapaces of Eastern Box Turtles were recovered from this site. This turtle is recorded from the modern fauna of Kent County (Holman 2004). Site 3. Juntunen Site (20MK1), Bois Blanc Island, Mackinac County, Michigan (Cleland 1966; Adler 1968). Age Late Woodland. Remarks This species has not been recorded in the modern fauna of Bois Blanc Island and occurs well outside of its present range in North America at this site (Adler 1968). Thus, the presence of Eastern Box Turtle remains at this site is probably from intertribal trading. Site 4. Spring Creek Site (20MU3), Egelston Township, Muskegon County, Michigan (Martin 1990). Age Late Woodland. Remarks This species has been recorded from the modern fauna of Muskegon County, Michigan (Holman 2004). Site 5. Moccasin Bluff (20BE80), north of Buchanan, Berrien County, Michigan (Cleland 1966; Adler 1968; Betteral and Smith 1973).

3. Quaternary Remains of Michigan Amphibians and Reptiles

Age Late Woodland, Late Mississippian cultural unit. Remarks This species has been recorded in the modern fauna of Berrien County (Holman 2004). Site 6. Wymer West Knoll Site (20BE132), Berrien County, Michigan (Martin and Richmond 2001). Age Late Woodland, Late Mississippian cultural unit. Remarks This species has been recorded from the modern fauna of Berrien County (Holman 2004).

Trachemys scripta (Schoepff 1792) Pond Slider Site Schultz Site (20SA2), at the confluence of the Tittabawassee and Shiawassee Rivers, Saginaw County, Michigan (Adler 1968). Age Middle Woodland. Remarks This turtle has not been recorded in the modern fauna of Saginaw County (Holman 2004), but it is possible that this species occurred naturally in Saginaw County during Schultz Site times (Adler 1966; Holman 2001b).

Family Kinosternidae Sternotherus odoratus (Latreille 1901) Eastern Musk Turtle Site 1. Bear Creek Site, St. Charles Township, Saginaw County, Michigan (Smith in Branstner and Hambacher 1994). Age Middle Archaic through early Late Woodland.

Remarks This species has not been recorded in the modern fauna of Saginaw County (Holman 2004). There is a very distinct possibility that this animal presently occurs there. Site 2. Kline 1 Site (20SJ29), near Portage Lake, St. Joseph County, Michigan (Cremin et al. 1990). Age Late Woodland. Remarks This species is recorded in the modern fauna of St. Joseph County (Holman 2004).

Family Trionychidae Apalone spinifera (Lesueur 1927) Spiny Softshell Site 1. Rock Hearth Site (20BE306), St. Joseph River, Oronoko Township, Berrien County, Michigan (Higgins 1990). Age Late Archaic. Remarks The Spiny Softshell is recorded in the modern fauna of Berrien County (Holman 2004). Site 2. Bear Creek Site (20SA1043), St. Charles Township, Saginaw County, Michigan (Smith in Branstner and Hambacher 1994). Age Middle Archaic to early Late Woodland. Remarks This species has not been recorded from the modern fauna of Saginaw County but probably occurs there (Holman 2004). Site 3. Schmidt Site (20SA192), near Bridgeport, Saginaw County, Michigan (Cleland 1966; Adler 1968).

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The Amphibians and Reptiles of Michigan

Age Late Archaic. Remarks This species is not recorded in the modern fauna of Saginaw County but probably occurs there (Holman 2004). Site 4. Cassasa Site (20SA1021), near St. Charles, Saginaw County, Michigan (Smith and Chiles-Artymko 1995).

Age Late Woodland. Remarks This species is not recorded in the modern fauna of Saginaw County but probably occurs there (Holman 2004).

Age In both the Middle Woodland and Late Woodland components of the site.

Site 8. Kline 1 Site (20SJ29), near Portage Lake, St. Joseph County, Michigan (Cremin et al. 1990).

Remarks This species is not recorded in the modern fauna of Saginaw County but probably occurs there (Holman 2004).

Age Late Woodland.

Site 5. Marquette Viaduct Site (20BY28), Bay City, Bay County, Michigan (Lovis et al. 1996). Age Middle Woodland component of the site. Remarks This turtle is not recorded in the modern fauna of Bay County (Holman 2004). Site 6. Schultz Site (20SA2), at the confluence of the Tittabawassee and Shiawassee Rivers, Saginaw County, Michigan (Cleland 1966, Shipman 2004). Age Middle Woodland. Remarks This species is not recorded in the modern fauna of Saginaw County but probably occurs there (Holman 2004).

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Site 7. Foster Site (20SA74), Taymouth Township, Saginaw County, Michigan (Bigony 1970).

Remarks This species has been recorded in the modern fauna of St. Joseph County (Holman 2004). Site 9. Stadelmeyer Site (20SA195), near the city of Saginaw, Saginaw County, Michigan (Bigony 1970). Age Late Woodland. Remarks This species has been recorded in the modern fauna of St. Joseph County (Holman 2004). Site 10. Allegan Dam (20AE56), Allegan County, Michigan (Spero 1979). Age Late Woodland, Late Mississippian cultural unit. Remarks This species has been recorded in the modern fauna of Allegan County (Holman 2004).

3. Quaternary Remains of Michigan Amphibians and Reptiles

Site 11. Moccasin Bluff (20BE8), north of Buchanan, Berrien County, Michigan (Cleland 1966; Adler 1968; Betteral and Smith 1973). Age Late Woodland, Late Mississippian cultural unit. Remarks This species has been recorded in the modern fauna of Berrien County (Holman 2004). Site 12. Wymer West Knoll (20BE132), Berrien County, Michigan (Martin and Richmond 2001). Age Late Woodland, Late Mississippian cultural unit. Remarks This species has been recorded in the modern fauna of Berrien County (Holman 2004).

Family Colubridae Nerodia Baird and Girard 1953 North American Watersnakes Site Stadelmeyer Site (20SA195), near the city of Saginaw, Saginaw County, Michigan (Bigony 1970). Age Late Woodland. Remarks The only species of Nerodia that presently occurs in Saginaw County is the Common Watersnake, Nerodia sipedon sipedon (Holman 2004).

Pantherophis gloydi (Conant 1940) Eastern Foxsnake Site Bear Creek Site (20SA1043), St. Charles Township, Saginaw County, Michigan (Branstner and Hambacher 1994; Holman 2001b).

Age Middle Archaic component of the site. Remarks This species has been recorded in the modern fauna of Saginaw County (Holman 2001b).

Thamnophis Fitzinger 1943 North American Gartersnakes Site 1. Schultz Site (20SA2), at the junction of the Tittabaswassee and Shiawassee Rivers, Saginaw County, Michigan (Cleland 1966). Age Middle Woodland. Remarks This material represents one of the three modern North American Gartersnakes that occur in the general area at present (see the range maps of the three Thamnophis species in the modern accounts). Site 2. Rock Hearth Site (20BE306), Oronoko Township, St. Joseph River, Berrien County, Michigan (Garland et al. 1990). Age Late Archaic. Remarks This material probably represents either Thamnophis sauritus or T. sirtalis, both of which occur in Berrien County today (Holman 2004). Site 3. Cassasa Site (20SA1021), near St. Charles, Saginaw County, Michigan (Smith and Chiles-Artymko 1995). Age Late Woodland.

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The Amphibians and Reptiles of Michigan

Remarks This material represents one of the three modern Gartersnakes that occur in the general area today (see the range maps of the three Thamnophis species in the modern accounts).

The Pleistocene By the end of the Pliocene epoch about 1.8 Ma BP, the herpetofauna of North America was essentially modern in nature (Holman 1995a). Unfortunately, no Pliocene vertebrate faunas remain in Michigan, but down the road near Swayzee in northeastern Indiana, an Early Pliocene herpetofauna is known (Farlow et al. 2001). This fossil assemblage is called the Pipe Creek Sinkhole biota. At this site, researchers have found fossil toads, American Bullfrogs, Leopard Frogs, Snapping Turtles, Painted Turtles, Slider turtles, Blanding’s Turtle, Hognosed Snakes, Racers, Smooth Greensnakes, Foxsnakes, Milksnakes, Gartersnakes, Watersnakes, and Massasaugas that were living with an extinct land tortoise and two odd, extinct genera of snakes left over from the Miocene. Strange extinct mammals—such as rhinos that resembled hippos, piglike peccaries, and a small camel—lived with these amphibians and reptiles. So did more common foxes and canids. Many or all of these animals probably lived farther north in Michigan too because the general climate was warmer than it is now. But the long warm spell that occurred in the Tertiary came to an abrupt end when the Pleistocene Ice Age began. Many adjustments had to be made by the North American herpetofauna, especially those species that occurred in Michigan, which was eventually completely covered by ice. Actually, two giant masses of ice moved into North America during the Pleistocene. The largest was the Laurentide Ice Sheet, which extended from Nova Scotia and the northeastern United States across the continent to western Canada. A smaller mass of ice, the Cordilleran Ice Sheet, blanketed the mountain ranges of the Northwest from Montana and Washington up to the Aleutian Islands. In North America, the Laurentide Ice Sheet reached the farthest south in the central Great Lakes region (see fig. 4). The most southern penetration was during the Illinoian glacial stage when the ice extended to the extreme southern parts of Illinois, Indiana, and Ohio. During the last glaciation of the Pleistocene in North

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America, the Wisconsinan, the ice did not extend quite as far south in these states. Because of the scouring effects of earlier glaciations in Michigan, most of our knowledge of glacial events in Michigan is from the late part of the Wisconsinan. About 20 ka BP, the ice blanketed huge blocks of former amphibian and reptile habitat in Illinois, Indiana, and Ohio, and completely covered every inch of Michigan from north to south. The ice sheet was up to two miles thick in some areas. Additional ice advances in these Great Lakes states occurred at intervals of about one thousand years before the final Wisconsinan advance extended into northern Indiana and Ohio, about 15 ka BP (Holman 2001a). About 14 ka BP, the ice began its final withdrawal in the Midwest and exposed the land for recolonization by amphibians and reptiles as well as other forms of life. The cold climate and ice advances vastly changed the climate and topography that Great Lakes amphibians and reptiles had been adapted to for countless thousands of years. The ice sheets drastically changed the landscapes over which they passed. The thickness of the ice varied from place to place, but it has been estimated that the average thickness was about 1.25 miles and that in places it was 2 miles or more thick. Valleys, winding ridges, various types of wide ridges, rounded and flat hills, lakes (including the Great Lakes), potholes, streams, swamps, and bogs were all formed as the result of glacial activity. All of these features influenced the ecology of the reinvading amphibians and reptiles. Before the Ice Age, the amphibians and reptiles of Michigan lived in a relatively warm, dry, uplifted area, probably somewhat similar to the high plains of the central United States (e.g., in North and South Dakota, Nebraska, Kansas, Oklahoma, and northern Texas). After the Ice Age, they lived in a cooler, moister, topographically depressed Michigan, with the landscape highly modified by the previous glacial events. During the Pleistocene, Michigan experienced several major and probably many minor glacial advances and retreats. Major advances were called “glacial ages” and major retreats were called “interglacial ages” (see Holman 2001a). However, the classic notion of alternating cold glacial and warm interglacial climates is now considered to be oversimplified. Modern evidence in North America indicates that the climate was cold in areas near the

3. Quaternary Remains of Michigan Amphibians and Reptiles

borders of the ice sheet, but the climate in the central and southern United States is believed to have been more equable than it is today, with warmer winters and cooler summers. This Pleistocene climate south of the ice sheets is importantly related to physiological adaptations in amphibians and reptiles of the region. Vegetational communities were obviously greatly affected by the advancing and retreating ice sheets in the Great Lakes region. Michigan was the only state in the region that was completely overrun by this huge mass of ice; all the vegetational communities as well as the herpetofauna were completely obliterated by this event. The land under this mile or two of ice must have been covered for many thousands of years at a time. Each time the glacier retreated, communities reformed on essentially sterile piles of mud, sand, and rocks left behind and exposed by the melting glacier. The classic idea is that major vegetational associations were caused to withdraw southward in bandlike units by the advancing ice, and that these units moved northward again as the ice retreated (Holman 2001a, 13, fig. 8). It was thought that in the eastern United States during glacial times, a barren tundra association existed in a deep band south of the glacial front and that this band was bordered by a band of coniferous forest that graded into temperate deciduous forest which penetrated far into the southeast. This classic hypothesis is often called the “stripe hypothesis.” The modern theory is that during a large portion of the Pleistocene, a cold climate and tundra or coniferous vegetation existed in areas rather near the glacier but that vegetational communities in the central and southern United States existed as a mixture of the original plants in the area coexisting with invading northern forms. This idea has arisen from the concept that plant and animal species reacted individually rather than in groups to Ice Age changes and that the mixed communities in the region would have been able to coexist in the equable climates that existed during those times. This idea is often referred to as the “plaid hypothesis.” During the Ice Age, so much of the water in the world was bound up in the ice sheets that sea levels fell. For example, in Florida, the peninsula greatly enlarged as the sea withdrew during glacial times. During interglacial times, however, sea and lake levels rose considerably. In the Great Lakes region, the Great Lakes themselves

rose and fell, as did large rivers such as the St. Lawrence in Canada. Incidentally, a perfectly preserved Leopard Frog was found and described from muddy Pleistocene sediments of the St. Lawrence (Holman 2003, frontispiece). The Wisconsinan is the only well-documented Pleistocene stage in Michigan. Several warmer periods during the generally cold Wisconsinan led to the temporary withdrawal of the ice sheets in the Great Lakes region. These warmer periods are called “interstadials.” The fact that ice withdrew from the southern part of the Lower Peninsula of Michigan about 25 ka BP is confirmed by a fossil duck dated at about 25,000 radiocarbon years old that was found in a water well site in Muskegon County, and a mammoth dated at about 24,000 radiocarbon years old that was found during the digging of a farm pond in Midland County. This interstadial is called the Plum Point interval (Holman 2001a). Unfortunately, no amphibians or reptiles have been found in any Michigan interstadial sites.

The Amazing Survival of Amphibians and Reptiles during the Pleistocene In spite of all the Pleistocene stresses undergone by the amphibians and reptiles in North America, no amphibians and reptiles became extinct during this epoch except some large tortoises. On the other hand, eight families, forty-six genera, and about 191 species of mammals suffered extinction during the North American Pleistocene (Holman 1991). The adaptations of North American amphibians and reptiles that were helpful during Ice Age stresses are likely several. It appears obvious that ectothermic (cold-blooded) animals such as amphibians and reptiles, which can successfully live in various shelters at low temperatures and with very little oxygen, would have many advantages over the endothermic (warm-blooded) birds and mammals during extended cold spells. The known ability of some amphibians and reptiles to freeze solid in winter and thaw out in the spring with no harmful effects certainly would have been helpful during the Pleistocene. The small body size of many northern temperate amphibians and reptiles must have been advantageous to them when habitats were scarce during the Pleistocene, especially compared to the large, now-extinct mammals

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The Amphibians and Reptiles of Michigan

that occurred in Michigan at the time. Such large mammals need exceptionally large tracts of habitat in which to exist (Owen-Smith 1987). Large concentrations of small amphibians and reptiles have been found in recent Michigan from time to time. A distinct possibility is that few small amphibians and reptiles were directly dependent on the giant mammals (e.g., mastodonts and mammoths) either as scavengers or as commensals (one species that benefits from a common food supply while the other is not affected). For example, at the famous Pleistocene site at Rancho La Brea, California, the scavenging commensal birds and dung beetles that were dependent on the large herbivorous mammals became extinct along with those mammals (Harris and Jefferson 1985). All the amphibian and reptilian species survived to the present though. In contrast, in Australia the Pleistocene Giant Monitor Lizard and the huge snake Wonambi were top predators and became extinct because so many of the large marsupial mammals that they fed upon died out. Parenting in birds and mammals is a reproductive stress, and it would appear to have been a great drain on their energy budgets during a time of climatic change. Parenting is mainly lacking in most amphibians and reptiles other than crocodilians. Moreover, the higher reproductive potential of amphibians and some reptiles, compared especially with large mammals, such as mastodonts and mammoths, would appear to favor the amphibians and reptiles during times of climatic change. For more than three decades, the hypothesis of human overkill has been put forward as a reason for the extinction of the many large mammals that lived during the Pleistocene (see Martin and Klein 1984). Holman (1959) compared the low extinction percentages of amphibians and reptiles to those of mammals in a Pleistocene fauna in Florida and suggested the rise of humans might have been an important factor in this. This might reflect the lesser desirability of most amphibians and reptiles as food compared with the sizeable number of large mammals that were available at the time. On the other hand, the easily obtained giant tortoises of the genus Hesperotestudo were eaten by humans during the Florida Pleistocene (Clausen et al. 1979) and this could have been a major cause of the extinction of those tortoises. Many Michigan archaeological sites have yielded large turtles, but very few have yielded small

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amphibians and reptiles. Apparently, sometimes it is important to be small and slimy or scaly. Where did the Michigan amphibians and reptiles go when the state was covered with ice? Stuart (1979, 14) stated, relative to his studies in Britain, that “fluctuations in climate are the outstanding characteristics of the Pleistocene.” He later implied that cold spells came on very rapidly at times and pointed out that the most recent cold spell lasted about ten times as long (100,000 years) as the warm spell (10,000 years) that preceded it. He also pointed out that this may have been the trend during the entire Pleistocene, which we now believe was about 1.8 million years in duration. Many populations of amphibians and reptiles in Michigan may have died under the ice sheet during the last glaciation before they could migrate southward. Therefore, when talking about “re-entrant post-glacial amphibians and reptiles” (Holman 2004), the subject may be “starter populations” whose direct ancestors had never been in the Michigan land area. Studies of Pleistocene amphibians and reptiles in the Great Lakes region are rare. The few late Pleistocene herpetofaunas that have been documented from recently deglaciated sites in Indiana and Ohio have yielded the remains of amphibians and reptiles, almost all of which occur in Michigan today. The following paragraphs describe some of these sites. The Prairie Creek D Site occurs in Daviess County in southwestern Indiana (Holman and Richards 1993). The fossils come from ancient Lake Prairie Creek that occurred in the Late Wisconsinan from about 16 to about 13 ka BP. The Prairie Creek D Site itself represents a time of about 14 ka BP. The complete fossil assemblage from the site suggests a mosaic of habitats, including coniferous stands, mixed deciduous and coniferous forest, some pure deciduous forests, and grassy areas. This fauna thus fits perfectly with the plaid hypothesis of a vegetational mosaic previously mentioned. The following are the Prairie Creek D amphibians and reptiles that have been found: Ambystoma species, Bufo species, Rana catesbeiana, Rana clamitans, Rana pipiens group, Rana sylvatica, Chelydra serpentina, Chrysemys picta, Emydoidea blandingii, Graptemys species, Pseudemys species, Sternotherus odoratus, Apalone spinifera, Apalone species, Nerodia erythrogaster, Nerodia species, and Thamnophis species. All of these

3. Quaternary Remains of Michigan Amphibians and Reptiles

animals except the Cooter Turtle (Pseudemys) presently occur in the southern peninsula of Michigan. Figure 106 shows fossil remains of some of the reptiles from this site. The Christensen Bog Mastodont Site near Greenfield (17 miles east of Indianapolis) in Hancock County yielded bones representing two mastodonts as well as amphibians, reptiles, birds, and mammals. Christensen Bog itself is an oval depression that formed originally as a kettle lake created by wasting glacial ice. The amphibians and reptiles listed here come from a unit in the bog that was radiocarbon

dated at about 13,000 to about 14,000 radiocarbon years ago. These animals consist of Rana pipiens group, Chelydra serpentina, Chrysemys picta, and Apalone species (fig. 107). All of these species occur in the Lower Peninsula of Michigan at present.

FIG. 107. Left group: Chrysemys picta (Painted Turtle) shell from the Late Wisconsinan Christensen Bog Mastodont Site, Hancock County, Indiana: (A) carapace in dorsal view, (B) carapace in ventral view, (C) plastron in dorsal view, and (D) plastron in ventral view. Each scale bar represents 10 mm. Right group: From the same site, left humerus of Chelydra serpentina (Snapping Turtle) in anterior (left) and posterior (right) views. Illustration by Jane Kaminski.

FIG. 106. Diagnostic turtle bones identified from the Prairie Creek D Site, Daviess County, Indiana: (A) nuchal bone of Chrysemys picta (Painted Turtle) in dorsal view, (B) nuchal bone of Emydoidea blandingii (Blanding’s Turtle) in dorsal view, (C) peripheral bone of Graptemys sp. (Map Turtle) in dorsal view, (D) nuchal bone of Terrapene carolina (Eastern Box Turtle) in dorsal view, (E) nuchal bone of Trachemys scripta (Pond Slider) in dorsal view, and (F) nuchal bone of Sternotherus odoratus (Eastern Musk Turtle) in dorsal view. Each scale bar represents 10 mm. Illustration by Irene Rinchetti.

The Sheriden Pit Cave Site is found in Wyandot County, in northwestern Ohio (Holman 1997). This site has yielded the most diverse amphibian and reptile fauna known from Ohio. A series of radiocarbon dates from the cave sediments indicate an age of about 11,700 radiocarbon years ago. The eighteen species of amphibians and reptiles known from the Sheriden Pit Cave form the largest Pleistocene herpetofauna known from the Great Lakes basin: Ambystoma laterale group, Bufo americanus, Bufo fowleri, Pseudacris triseriata, Rana catesbeiana, Rana clamitans, Rana pipiens, Rana sylvatica, Chelydra serpentina, Chrysemys picta, Emydoidea blandingii, Coluber constrictor, Lampropeltis triangulum, Nerodia sipedon, Opheodrys vernalis, Pantherophis gloydi or vulpinus (fig. 108), Regina septentrionalis, and Thamnophis sirtalis (fig. 108). All of the species in this group can be found in the southeastern part of the Lower Peninsula of Michigan at present.

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The Amphibians and Reptiles of Michigan

species to move 100 km (62 mi.) northward during postglacial time. The estimate is obviously crude, but it does show that groups of amphibian species may require a long time to naturally reoccupy a large geographic area—in fact many human lifetimes. Such a slow rate of reoccupation by amphibians and reptiles during the Pleistocene may indicate that intentional reintroduction of modern species to suitable habitats could sometimes be warranted.

Patterns of Herpetological Reoccupation of Postglacial Michigan

FIG. 108. Upper group: Thamnophis sirtalis (Common Gartersnake) vertebra from the Late Wisconsinan Sheriden Pit Cave Site, Wyandot County, Ohio: (A) lateral, (B) posterior, (C) anterior, (D) dorsal, and (E) ventral views. Lower group: vertebra of a Foxsnake (either Pantherophis gloydi or P. vulpinus) from the same site: (A) lateral, (B) posterior, (C) anterior, (D) ventral, and (E) dorsal views. Illustration by Teresa Petersen.

How Rapidly Amphibians and Reptiles Returned to Michigan If someone asked the question “Are there any aspects of Pleistocene herpetological studies that might pertain to the future?” it could be answered with another question: “If future amphibian populations become completely extirpated from huge geographic areas, at what rate might one expect recolonization to occur?” Looking at Pleistocene reinvasion patterns as analogs might be instructive. Four species of anurans (Rana catesbeiana, R. clamitans, R. pipiens, and R. sylvatica) co-occur in the Prairie Creek D Site (about 14.5 ka BP) in southwestern Indiana and in the Sheriden Pit Site (about 11.7 ka BP) in northwestern Ohio (fig. 109). The latitudinal distance between the two sites is about 280 km (174.0 mi.). The time difference between them is about 2,800 years. Assuming that each of these populations represent the earliest amphibian reinvaders of the area, the mean rate of movement would be about 0.1 km (328 ft.) per year. This rate of movement would indicate that it took an average of about one thousand years for the four frog

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I have suggested two major routes of entry for the postglacial reoccupation of Michigan by amphibians and reptiles: (1) a wide corridor through Indiana and Ohio into the Lower Peninsula of Michigan and (2) a somewhat narrower corridor through Wisconsin into the Upper Peninsula (fig. 110). Lesser invasions could have occurred from Ontario into one or both peninsulas, but I think few species were able to invade the Upper Peninsula across the Straits of Mackinac (see Holman Table 3. Herpetological taxa considered to be primary invaders of postglacial Michigan Amphibians

Reptiles

Ambystoma laterale

Chelydra serpentina

Ambystoma maculatum

Chrysemys picta

Ambystoma tigrinum

Emydoidea blandingii

Hemidactylium scutatum

Glyptemys insculpta

Plethodon cinereus

Graptemys geographica

Necturus maculosus

Plestiodon fasciatus

Notophthalmus viridescens

Diadophis punctatus

Bufo americanus

Lampropeltis triangulum

Hyla chrysoscelis

Nerodia sipedon

Hyla versicolor

Opheodrys vernalis

Pseudacris crucifer

Pantherophis vulpinus

Pseudacris maculata

Storeria dekayi

Pseudacris triseriata

Storeria occipitomaculata

Rana catesbeiana

Thamnophis sauritus

Rana clamitans

Thamnophis sirtalis

Rana palustris Rana pipiens Rana septentrionalis Rana sylvatica

3. Quaternary Remains of Michigan Amphibians and Reptiles

FIG. 109. Locations of Late Pleistocene herpetological sites in Michigan, Indiana, and Ohio: PC, Prairie Creek D Site, Daviess County, Indiana; CB, Christensen Bog Mastodont Site, Hancock County, Indiana; SP, Sheriden Pit Cave Site, Wyandot County, Ohio; SM, Shelton Mastodont Site, Oakland County, Michigan; WW, Meskill Road Water Well Site, St. Clair County, Michigan. Illustration by the author.

1992). I also developed a model for herpetological reoccupation of postglacial Michigan based on an interpretation of geological data, paleobotanical and paleovertebrate assemblages in the state, and ecological tolerances of the modern herpetofauna. It seems to me that three categories of reinvading amphibians and reptiles were likely: “primary invaders,” consisting of species that may be found in coniferous forest areas today, along with the tundra Wood Frog (Rana sylvatica) (see table 3); “secondary invaders,” consisting of species that extend into the mixed conifer–broadleaf areas of the Lower Peninsula today but do not occur in the Upper Peninsula except for certain rare occurrences (table 4); and “tertiary invaders,” consisting of species that are all

confined to the broadleaf area in the state (table 5). (The tables have been slightly modified from their original publication.) The fact that the Holocene epoch had alternating warm and cold spells as well as moist and dry periods as in the Pleistocene has been significant in the development of the modern herpetofauna now present in Michigan. Unfortunately, very few Holocene herpetofaunas have been documented in the state. The most significant site is the Harper Site in Shiawassee County, in the southcentral Lower Peninsula.

Table 4. Herpetological taxa considered to be secondary invaders of postglacial Michigan Amphibians

Reptiles

Bufo fowleri

Clemmys guttata

Acris crepitans

Terrapene carolina Trachemys scripta Sternotherus odoratus Apalone spinifera Coluber constrictor Heterodon platirhinos Pantherophis spiloides Pantherophis gloydi Regina septemvittata Thamnophis butleri Sistrurus catenatus

FIG. 110. The Great Lakes region showing (1) the major routes of herpetological recolonization of postglacial Michigan (arrows), (2) the Mason-Quimby Line, and (3) the approximate maximum extent of the Laurentide Ice Sheet (heavy line) in Wisconsin, Illinois, Indiana, and Ohio. Illustration by the author.

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Table 5. Herpetological taxa considered to be tertiary invaders of postglacial Michigan Amphibians

Reptiles

Ambystoma opacum

Aspidoscelis sexlineata

Ambystoma texanum

Clonophis kirtlandii

Siren intermedia

Nerodia erythrogaster

The plants and animals of the Harper Site accumulated between 6,850 and 6,647 radiocarbon years ago (Stuiver and Reimer 2003) in a shallow lake. The herpetofauna consisted of four turtles—the Painted Turtle (Chrysemys picta), Spotted Turtle (Clemmys guttata), Blanding’s Turtle (Emydoidea blandingii), and the Eastern Musk Turtle (Sternotherus odoratus)—with a variety of other animals, including remains of ducks, elk, whitetailed deer, and countless numbers of invertebrate shells, wood, coniferous cones, seeds, and plant fiber. Analysis of pollen from the site indicates the prominent tree species were maple, oak, elms, birches, and hornbeams. The presence of both the turtles and the other fauna indicate the climate then was at least as warm as it is today. Findings at Dolomitic Fissure Site 1, a Late Holocene site in Mackinac County in the eastern part of the Upper Peninsula of Michigan, have yielded a mammalian fauna that suggests the area may have been colder than it is at present. An American Toad (Bufo americanus) and Spring Peeper (Pseudacris crucifer) recovered from the site offer little to confirm or deny that the climate may have been colder during the deposition of the bones. Many more dated Holocene herpetological sites in Michigan are needed to answer the climate question with any certainty.

Archaeological Sites Archaeological sites not only give us information about the relationships of native people to Michigan amphibians and reptiles but supplement the records of Michigan amphibians and reptiles through time gleaned from Holocene sites. The following list contains in chronological order some selected examples of Michigan amphibians and reptiles that are clearly recorded from specific cultural periods. The counties in which the sites are located are included in parentheses following the species.

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Middle Archaic (8,000 to 5,000 years BP) Chrysemys picta (Saginaw) Pantherophis gloydi or vulpinus (Saginaw) Late Archaic (5,000 to 3,000 years BP) Chelydra serpentina (Berrien, Saginaw) Chrysemys picta (Bay, Berrien) Apalone spinifera (Berrien, Saginaw) Early Woodland (3,000 to 2,300 years BP) Thamnophis species (Saginaw) Middle Woodland (2,300 to 1,600 years BP) Bufo americanus (Saginaw) Rana catesbeiana (Saginaw) Chelydra serpentina (Bay, Mackinac, Saginaw) Chrysemys picta (Berrien, Saginaw) Clemmys guttata (Saginaw) Emydoidea blandingii (Bay, Kent, Saginaw) Graptemys geographica (Berrien, Saginaw) Terrapene carolina (Berrien, Kent, Saginaw) Trachemys scripta (Saginaw) Apalone spinifera (Bay, Saginaw) Thamnophis species (Saginaw) Late Woodland (1,600 to 350 years BP) Bufo species (Berrien, Gratiot) Rana catesbeiana (Saginaw) Rana species (Berrien, Charlevoix, Saginaw) Chelydra serpentina (Berrien, Gratiot, Mackinac [Bois Blanc Island], Saginaw) Chrysemys picta (Bay, Berrien, Charlevoix, Delta, Huron, Mackinac [Bois Blanc Island], Mason, Muskegon, Oceana, Saginaw) Emydoidea blandingii (Berrien, Gratiot, Mackinac [Bois Blanc Island], Oceana, Saginaw) Glyptemys insculpta (Mackinac [Bois Blanc Island]) Graptemys geographica (Saginaw) Terrapene carolina (Mackinac [Bois Blanc, Island], Muskegon) Sternotherus odoratus (St. Joseph) Apalone spinifera (Allegan, Berrien, Saginaw, St. Joseph) Nerodia species (Saginaw) Thamnophis species (Saginaw)

3. Quaternary Remains of Michigan Amphibians and Reptiles

As far as I am aware, only two amphibians have been identified to the generic and specific level in Michigan archaeological sites. American Bullfrogs (Rana catesbeiana) have been excavated in both Middle and Late Woodland sites in Saginaw County. The legs of American Bullfrogs are a gourmet item in the diet of many persons today; thus, the assumption could be made that these large frogs would have been eaten by the native people of Michigan. American Toads (Bufo americanus) are recorded from a Middle Woodland site in Saginaw County, and toads unidentified to species (Bufo sp.) were found in Late Woodland sites in both Berrien and Gratiot counties. These warty-skinned anurans were not likely eaten by people. Nevertheless, Dr. John Kilby, a former and distinguished teacher at the University of Florida, told me in 1959 that during the Great Depression in the early 1900s, hungry people in the Florida Panhandle would boil a variety of small animals in pots, and that toads commonly were among them. Boiling supposedly does not only denature the poison in the skin of toads but allows the skin to be easily peeled off these animals. The practice of boiling different species of animals together for human consumption during prehistoric times has been suggested for Michigan (M. B. Holman,

FIG. 111. A Pond Slider (Trachemys scripta) posterior peripheral bone from the Schultz Archaeological Site, Saginaw County, Michigan. The scale bar represents 10 mm. Illustration by Kraig Adler, from Adler (1968), courtesy of the Michigan Archaeologist.

pers. comm.), so it is not beyond the realm of possibility that toads were occasionally among the boilees during Holocene “Great Depression” times. Turtles are by far the most abundant reptiles recovered from archaeological sites in Michigan. The shell parts (fig. 111) and limb bones of turtles preserve very well compared to the bones of other amphibians and reptiles of Michigan. Frog and to a lesser extent toad bones are so thin and hollow that they disintegrate rapidly. Most salamander bones are very small and thin except for the humeri and vertebrae. Snake skull bones are numerous, but they too are very delicate. Only a few specialists are able to identify the scattered vertebrae of snakes that are occasionally found in archaeological sites. All of the ten species of turtles that presently occur in Michigan are found in combination in the archaeological sites of the state, and nearly all of them are represented in both the Middle and Late Woodland periods. Painted Turtles (Chrysemys picta) are the most abundant. Some of my herpetological colleagues have suggested that the abundance of the hardy Painted Turtle in Michigan today is a result of so many of the more specialized habitats of other Michigan turtles being destroyed by humans. True, Painted Turtles do quite well in muddy, polluted water, but Painted Turtles are also the most common reptiles that appear in the Pleistocene, Holocene, and archaeological sites of Michigan. I would suggest that Painted Turtles are by far the most common turtles in Michigan today because they are “slow-water generalists,” able to inhabit almost any pond, marsh, bog, slough, or slow river or stream in the state as long as there is either a muddy bottom or aquatic vegetation in which to hide. Moreover, they can eat and digest an amazing variety of plant and animal material. Regarding their interaction with humans during prehistoric and historic archaeological times in Michigan, turtles were certainly the most important reptile food items. Turtle bones that have been modified by cooking are easily identified because they have a characteristic blue or white color. Snapping Turtles and softshells are large and yield a significant amount of meat. I’ve seen that it differs in color, texture, and fat content depending on where it occurs in the turtle’s body. Snapping Turtle meat is sought after today, especially in northern regions (Carr

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1952). Softshell turtles were considered by Evermann and Clark (1916) to be the most highly regarded turtle item of food in Indiana. Painted Turtles are not an important food resource today, mainly because of their small size, although it is probable that native Americans added these animals to the boiling pot from time to time. Regarding Spotted Turtles, Carr (1952, 118) stated that “this species is too small to have any value as food for man.” Blanding’s Turtle is said to be very good to eat (Cahn 1937). Conant (1951) stated that in Ohio, large numbers of this turtle are caught and sent to market. I do not doubt that this moderately large turtle was occasionally used as a food resource by people in prehistoric and historic Michigan. For some reason, Northern Map Turtles have not been important food items during modern times. Cahn (1937) said it was caught in numbers by commercial fishermen in Illinois but was either thrown back or only used locally. About the Red-eared Slider, Cagle (1937) reported that several thousand pounds of dressed meat were shipped from Reelfoot Lake in Tennessee every year. Cahn (1937) related that the meat was of high quality and had a delicious flavor. I have no doubt these turtles were eaten in Michigan from time to time by both prehistoric and historic native people. The Red-eared Slider was reported from the Middle Woodland Schultz Site in Saginaw County, Michigan, by Adler (1968) (fig. 111). Turtles were not only eaten by people in prehistoric times in Michigan but their shells were modified to be used as utensils and ceremonial or religious objects. In Archaic times, a Painted Turtle carapace from the Late Archaic Rock Hearth Site in Berrien County, Michigan, was modified as a utensil (Garland et al. 1990). In Late Woodland times Painted Turtles from Site No. 0910-01-328 in the Hiawatha National Forest in Delta County were modified by humans into bowls and rattles (Weir and Anderton 1991). Middle Woodland sites in Kent and Saginaw counties have yielded the most abundant and perhaps the most interesting turtle remains modified by humans. The Norton Mounds, located on the south bank of the Grand River only three miles from Grand Rapids are now preserved in Indian Mound Park. In 1964, excavations at this site produced fifteen bowls made from the carapaces of turtles (Halsey 1966). The internal

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FIG. 112. Engraved turtle shells, all from Blanding’s Turtles (Emydoidea blandingii), from the Norton Mounds and Schultz Archaeological Site in Michigan. Illustration by John Halsey, from Halsey (1966), courtesy of the Michigan Academy of Science, Arts, and Letters.

structures of these carapaces (such as the vertebrae that adhere to the top of turtle shells) were cut and ground off. The thick edges were also ground down, and the entire inner surface was smoothed with an abrading agent, possibly sandstone. Of the fifteen shells found, thirteen were from Blanding’s Turtles. The other two shells were from Eastern Box Turtles. Only the Blanding’s Turtle shells were engraved (fig. 112). It was apparent to Halsey (1966) from the association of turtle carapace bowls with conch-shell dippers, pottery vessels, bone pins and awls, and notched clam-shell spoons that some kind of household assemblages were represented in these mounds. Thus Halsey argued that the bowls were intended for everyday use rather than for sacrificial offerings. The artist who decorated the turtle shells appeared to show more imagination and latitude than those who decorated the pottery found at the site. Two years of excavations in 1963 and 1964 at the Middle Woodland Schultz Archaeological Site at the junction of the Tittabawassee and Shiawassee Rivers in

3. Quaternary Remains of Michigan Amphibians and Reptiles

Saginaw County, Michigan, yielded at least five engraved shell bowls and several other fragmentary bowls that were not engraved. Almost all of the turtle shells removed from the Schultz Site were modified by humans in one way or another. Two engraved shells at the Schultz Site represented Blanding’s Turtle, while one small, fragmentary, unengraved bowl represented a Painted Turtle. Later, Murray (1972) found plain dishes made from Blanding’s Turtles and Painted Turtles and engraved dishes made from Blanding’s Turtles at the Schultz Site. He also found bangles made from both Blanding’s Turtles and softshell turtles at this site.

Modern Amphibians and Reptiles in Michigan The condition of the modern herpetofauna in Michigan is undoubtedly, in many ways, a result of human modification of the environment. On the other hand, herpetological habitats have previously been completely obliterated in all of Michigan by Pleistocene ice masses and then reoccupied by amphibians and reptiles, probably several times. This departure and rearrival process probably occurred in a relatively random fashion rather than by an orderly march of plant and animal species southward or northward. Some Michigan herpetological species were left as relicts after the Middle Holocene warm, dry spell (hypsithermal event) was replaced by a cooler climate, especially the “Little Ice Age” that occurred only a few hundred years ago (Bernabo 1981; Kapp 1999; Holman et al. 2003). Undoubtedly, some herpetological species are in the process of reoccupying new habitats today (Holman 1992). The modern amphibians and reptiles that live within the four Michigan Regional Landscape Ecosystems (MRLE), first discussed in part 1, are the survivors of the Pleistocene, and much that is of interest about them is easier to understand within the four-category structure. Briefly, the MRLE units are numbered I to IV, and Region I is essentially the bottom half of the Lower Peninsula, and Region II is the top half of this Peninsula. Region III is essentially the eastern half of the Upper Peninsula, and Region IV is the western half. The topics covered in these final pages are (1) the herpetological species diversity in each of these four divisions; (2) presence of primary, secondary, and

tertiary postglacial reentrant taxa that occur in each of the four ecological divisions; (3) relict taxa in these divisions; and (4) herpetological species that appear to be presently in the process of reoccupying new habitats; also discussed are (5) the amphibians and reptiles of the Lake Michigan Island Archipelago and a very large ancient Lake Michigan island that is now part of the mainland.

Species Diversity Region I is the most herpetologically diverse of the four MRLE in Michigan, as it is home to twenty-two species of amphibians and twenty-nine of reptiles—a total of fifty-one species. Region II is next most diverse with nineteen species of amphibians and twenty-seven of reptiles—a total of forty-six species. In the Upper Peninsula, Region III has eighteen species of amphibians and fifteen species of reptiles—a total of thirtythree species—and Region IV has eighteen species of amphibians and sixteen species of reptiles—a total of thirty-four (Holman 2004). Region I has 94.4 percent of the herpetological species that occur in the entire state of Michigan. The three species missing from Region I are the Boreal Chorus Frog (Pseudacris maculata), which occurs only on Isle Royale, and the Mink Frog (Rana septentrionalis) and Western Foxsnake (Pantherophis vulpinus), which occur only in the Upper Peninsula. Region II has 90.2 percent of the amphibian and reptile species that occur in Region I. In the Upper Peninsula, Region III has only 64.7 percent and Region IV has only 66.7 percent of the number of amphibian and reptile species that are found in Region I. Among other factors, this pattern of greater species numbers in the Lower Peninsula undoubtedly reflects the warmer temperatures over the years and greater habitat diversity of Region I and Region II. Comparing the diversity of amphibian species in these four regions shows that amphibian species diversity is somewhat higher in Region I than in the other three ecological regions (II, III, and IV) but is very similar within the other three. Region II has 86.4 percent, Region III 81.8 percent, and Region IV 81.8 percent of the number of amphibian species found in Region I. When comparing the regional diversity of reptile species, however, a striking difference is apparent from that of the Michigan amphibians. Region II has 93.1 percent, Region III only 51.5 percent, and Region IV

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only 55.2 percent of the number of reptile species found in Region I. In other words, only about half as many reptile species live in Regions III and IV as exist in Region I. This situation no doubt reflects the cooler temperatures and fewer habitats for reptiles in Regions III and IV, but other factors are probably affecting reptile distribution as well.

Postglacial Reentrant Amphibian and Reptile Taxa in Michigan The primary, secondary, and tertiary postglacial reentrant amphibians and reptiles in Michigan are defined and discussed in part 2 (see especially tables 3, 4, and 5). Here I will explain these species within the framework of the present MRLE distribution of amphibians and reptiles in the state. Region I is unique in having tertiary species (the latest reentrants) that do not occur in any of the other three regions in the state. These species are the Marbled Salamander (Ambystoma opacum), Small-mouthed Salamander (Ambystoma texanum), Western Lesser Siren (Siren intermedia nettingi), Six-lined Racerunner (Aspidoscelis sexlineata), Kirtland’s Snake (Clonophis kirtlandii), and Copper-bellied Watersnake (Nerodia erythrogaster neglecta). These late reinvading species may have extended farther north during the mid-Holocene Hypsithermal Interval and then withdrawn to their present range during the Late Holocene cool spell that terminated in the Little Ice Age. Regions III and IV contain mainly primary (first reentrant) amphibians and reptiles. These species are the Blue-spotted Salamander (Ambystoma laterale), Spotted Salamander (Ambystoma maculatum), Tiger Salamander (Ambystoma tigrinum), Four-toed Salamander (Hemidactylium scutatum), Eastern Red-backed Salamander (Plethodon cinereus), Common Mudpuppy (Necturus maculosus), Central Newt (Notophthalmus viridescens louisianensis), Eastern American Toad (Bufo americanus americanus), Cope’s Gray Treefrog (Hyla chrysoscelis), Gray Treefrog (Hyla versicolor), Northern Spring Peeper (Pseudacris crucifer crucifer), Boreal Chorus Frog (Pseudacris maculata), Western Chorus Frog (Pseudacris triseriata), American Bullfrog (Rana catesbeiana), Northern Green Frog (Rana clamitans melanota), Pickerel Frog (Rana palustris), Northern Leopard Frog (Rana pipiens), Mink Frog (Rana septentrionalis), Wood Frog (Rana sylvatica), Eastern Snapping Turtle (Chelydra serpentina serpentina), Painted Turtle (Chrysemys picta), Blanding’s

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Turtle (Emydoidea blandingii), Wood Turtle (Glyptemys insculpta), Northern Map Turtle (Graptemys geographica), Five-lined Skink (Plestiodon fasciatus), Northern Ringnecked Snake (Diadophis punctatus edwardsii), Eastern Milksnake (Lampropeltis triangulum triangulum), Western Foxsnake (Pantherophis vulpinus), Northern Watersnake (Nerodia sipedon sipedon), Smooth Greensnake (Opheodrys vernalis), DeKay’s Brownsnake (Storeria dekayi), Northern Red-bellied Snake (Storeria occipitomaculata occipitomaculata), Northern Ribbonsnake (Thamnophis sauritus septentrionalis), and Eastern Gartersnake (Thamnophis sirtalis sirtalis). Secondary postglacial reentrant species overlap in Regions I and II. These amphibians and reptiles are Fowler’s Toad (Bufo fowleri), Blanchard’s Cricket Frog (Acris crepitans blanchardi) (if the extralocal northern record for the state is correct—see the range map; otherwise it should be considered a tertiary species), Spotted Turtle (Clemmys guttata), Eastern Box Turtle (Terrapene carolina carolina), Red-eared Slider (Trachemys scripta elegans), Eastern Musk Turtle (Sternotherus odoratus) (if the extralocal record for the state is correct—see the range map), Eastern Spiny Softshell (Apalone spinifera spinifera), Blue Racer (Coluber constrictor foxii), Easten Hog-nosed Snake (Heterodon platirhinos), Central Ratsnake (Pantherophis spiloides), Eastern Foxsnake (Pantherophis gloydi), Queen Snake (Regina septemvittata), and Butler’s Gartersnake (Thamnophis butleri).

Relict Species Lincoln et al. (1982, 216) defined relict species as “persistent remnants of formerly widespread fauna or flora existing in isolated areas or habitats.” In the following paragraphs, I discuss possible relict herpetological species in Michigan region by region. Region I Of the salamanders, the Marbled Salamander (Ambystoma opacum) is part of an isolated population that is restricted to Berrien, Van Buren, and Allegan counties in extreme southwestern Michigan and the Lake Michigan dunes of Porter and LaPorte counties in extreme northwestern Indiana (Minton 2001). All five of these counties are contiguous and border Lake Michigan. They are separate from the continuous range of the species in Indiana, the northernmost point of which is in Carroll and Tippecanoe counties (Minton 2001, 53, map). I believe

3. Quaternary Remains of Michigan Amphibians and Reptiles

the most reasonable hypothesis is that this southwest Michigan–northwest Indiana population is a relict from the warmer Hypsithermal Interval of the Holocene, and it has been able to maintain itself because of the warming effect from nearby Lake Michigan. On the other hand, the Small-mouthed Salamander (Ambystoma texanum), which has been recorded only in Region I and only in the far southeast corner of the state in Livingston, Washtenaw, Wayne, Hillsdale, and Monroe counties, cannot be considered relict because it is contiguous with the widespread population of this species in Ohio (Pfingsten 1998, 228, fig. 25-11). It seems possible that the Small-mouthed Salamander could have extended its range northward in Michigan during the Hypsithermal Interval but then could have withdrawn somewhat during the cold spell of the Late Holocene. The Western Lesser Siren (Siren intermedia nettingi) is found only in Region I, where it has been recorded from only two counties, Van Buren and Allegan, in southwestern Michigan. Since this species is not known in the upper tier of counties in Indiana, except for a record in extreme southwestern Porter County (Minton 2001, 102, map), I suggest that the Western Lesser Siren is part of a relict population in Michigan that once may have extended farther north along the Traverse Corridor during the Hypsithermal Interval in the Holocene. Among the turtles, the Red-eared Slider (Trachemys scripta elegans) occurs mainly in Region I and a small portion of Region II. This species, which has been introduced in many parts of the world from the pet trade, has a modern range in the United States from Texas east to Mississippi and western Alabama and north to western Indiana through western Tennessee and most of Kentucky. Large isolated populations of this species live in southern Ohio and eastern Maryland (Conant and Collins 1998), along with smaller isolated populations in Regions I and II in Michigan (Holman 1994). Some of these populations, especially those in southeastern Michigan, are breeding populations that have been observed for decades (J. H. Harding, pers. comm.). Some would attribute all of these Red-eared Slider populations in Michigan to releases of animals bought as pets, but others argue that some of these populations may be relicts from hypsithermal times (Holman 1994). A record from the Middle Woodland Schultz Site in

Saginaw County was recovered from among the refuse of local animals used for food. Adler (1968) proposed that the Michigan record and another record from the Durst Archaeological Site at about the same latitude in south-central Wisconsin indicated that the range of the Red-eared Slider has been reduced in subsequent times. Concerning the lizards, the Six-lined Racerunner (Aspidoscelis sexlineata) is known on the basis of a single but thriving population in Tuscola County in the thumb area of Michigan. I have suggested that the population could be a relict left from the warm, dry times in the midHolocene (Holman 2001b). In about 1800 a corridor of tree-punctuated grasslands (grassland interspersed with open areas of gnarled oak species) extended from Berrien County in the southwestern corner of Michigan across the southern part of the state to within 20 kilometers (12.4 mi.) of Tuscola County (Dickmann and Leefers 2003, 102, map; 103–4). This Michigan corridor would connect today with the dune and prairie areas in northwestern Indiana in Lake, Porter, Laporte, Newton, Jasper, Pulaski, and Starke counties, all of which presently support populations of Aspidoscelis sexlineata (Minton 2001). Certainly the warmer, dryer Hypsithermal Interval during the mid-Holocene would have made this “corridor” even more accessible to this prairie species. Unless it can be demonstrated that someone or some group of persons has released a number of Six-lined Racerunners in the wild in this area of Tuscola County, I suggest that the “relict population” hypothesis is the most likely one—and I will admit that I have been feeding this “pet hypothesis” for years. The Kirtland’s Snake (Clonophis kirtlandii) is found in Michigan only in Region I, where records are known in the southwest in Berrien, Cass, Van Buren, Kalamazoo, Ottawa, and southern Muskegon County, and in Lenawee and Washtenaw counties in extreme southeastern Michigan. These are not true relict populations but are northern extensions of adjacent populations in Indiana and Ohio (see Minton 2001, 279, map; Conant 1951, 75, map). It is probable that this small snake extended farther north in Michigan during hypsithermal times. The large and conspicuous Copper-bellied Watersnake (Nerodia erythrogaster neglecta) occurs in Michigan only in the southern three tiers of counties. Specific counties where this species has been recorded

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are Cass, St. Joseph, Kalamazoo, Branch, Hillsdale, Eaton, and Oakland. This is a part of a large relict population that is contiguous in northeastern Indiana and northwestern Ohio (see Conant and Collins 1998; Minton 2001; Conant 1951). Region II Among the salamanders only isolated records of the Eastern Tiger Salamander (Ambystoma tigrinum tigrinum) exist for Region II. Here, this species has been reported only from Manistee, Clare, Crawford, and Otsego counties. These may be small relict populations because only the bottom three tiers of Region I have other records of this species in the Lower Peninsula. Also, all of Regions III and IV (other than an odd, mainly larval population in III) lack records of this species. On the other hand, Tiger Salamanders can be very secretive, spending most of their lives underground. The possibility exists that Michigan herpetologists have just not looked hard enough for this species. A case in point is that in 1940 Ambystoma tigrinum was unknown in the entire western half of the Florida Panhandle (Carr 1940), an area 129 km (about 80 mi.) long from east to west. But, at present the species is known to range throughout the Florida Panhandle (Conant and Collins 1998; Petranka 1998). Wilfred E. Neil (a well-known Florida herpetologist) told me in 1959 that to find Tiger Salamanders in northern Florida a person needed to be out in the woods on the very coldest and wettest midwinter nights with a flashlight. He added that most northern Floridians did not like to do that. It is somewhat possible that the populations of the Northern Map Turtle (Graptemys geographica) that occur in Roscommon and Grand Traverse counties are relict because no other records are known directly north or south of these counties in Region II. Also, a very isolated population of the Eastern Musk Turtle (Sternotherus odoratus) in the northeastern part of Region II may be relict. This species is recorded from only a single locality in Montmorency County. The nearest county record for this species in Michigan is in Newaygo County, far to the southwest. The same situation exists for the Eastern Spiny Softshell (Apalone spinifera spinifera), which has been recorded from Grand Traverse and Crawford counties in the northern part of Region II.

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Among the snakes, a clearly relict population of the Queen Snake (Regina septemvittata) occurs on Bois Blanc Island, which is in Lake Huron near Cheboygan in the extreme northern part of Region II. The nearest modern record of this species appears to be from Lake County to the southwest. Butler’s Gartersnake (Thamnophis butleri) has been recorded in what could be a relict population in Presque Isle and Alpena counties in the northeastern portion of Region II. The nearest record of this species is from Arenac County to the south. Region III Concerning salamanders, a single, mainly larval population of the Tiger Salamander (Ambystoma tigrinum) from Alger County represents the only record of this species from Region III in the Upper Peninsula. Incidentally, one of these larval specimens was 240 mm (9.4 in.) long (Hensley 1964). The nearest locality to Alger County where this species occurs is in Otsego County in Region II, approximately 282 km (174.8 mi.) to the south and east (Hensley 1964). A possible relict population of the Northern Map Turtle (Graptemys geographica) is known from east-central Schoolcraft County. The nearest known population of this species (also a possible relict population) is from Dickinson County some distance to the west. A population of the Blue Racer snake (Coluber constrictor foxii) occurs in Menominee County, bordering northeastern Wisconsin. This would appear to be a remarkable relict population because this species is otherwise confined far to the southwest in Wisconsin (Vogt 1981) and is well separated from this species in the western part of Region II in Michigan. Another snake, the Eastern Milksnake (Lampropeltis triangulum triangulum) has been reported from Region III only in the eastern part of Mackinac County. This population should probably be considered relict until additional collecting may prove the situation otherwise. The Midland Brownsnake (Storeria dekayi wrightorum) has been recorded in Schoolcraft and Delta counties in Region III. The next nearest occurrence of these populations is in southwestern Marinette County, Wisconsin (Vogt 1981). Region IV The Northern Map Turtle (Graptemys geographica) is known in Region IV only in Dickinson County.

3. Quaternary Remains of Michigan Amphibians and Reptiles

This is a probable relict population, as the species is not found in any of the three tiers of Wisconsin counties to the southwest (see Vogt 1981, 106, map). A possible relict population of the Eastern Milksnake (Lampropeltis triangulum triangulum) occurs in the upper tip of Marquette County, far from any other records in Michigan or Wisconsin; I wonder if this record may be a misidentified Western Foxsnake. A possible relict population of the Midland Brownsnake (Storeria dekayi wrightorum) is isolated in the counties of Baraga and Keweenaw in the northwestern part of Region IV.

Still “Coming Home”? Some Michigan reptile species may be extending their ranges northward yet today. Douglass (1977) detailed rather extensive range extensions of reptile species northward to Grand Traverse County. This county lies in the heart of the so-called Traverse Corridor of Michigan, where, because of its proximity to Lake Michigan and the prevailing southwesterly winds of the area, it has warmer mean annual temperatures than most of the inland areas at the same latitude. Examination of the range maps of Ruthven et al. (1928) alongside the Douglass range extensions of Graptemys geographica, Apalone spinifera, and Coluber constrictor makes the changes striking. But, as Douglass points out, the apparent changes may be partly because of early inadequate collecting in the northern part of the Lower Peninsula of Michigan. On the other hand, Ruthven and his colleagues would almost certainly have spotted these easily identified species during their jaunts throughout the state. Douglass (1977) did point out that the opening up of the forest by lumbering and other human ventures might have also created new habitats in the area for the sun-loving Coluber constrictor.

Lake Michigan’s Island Archipelago and a Large Ancient Island Once Part of the Mainland It is not surprising that the amphibians and reptiles that are most abundant and widespread on the mainland of Michigan are generally those found on the islands that surround the state (see the “Michigan Distribution” sections throughout the species accounts in part 2). However, Bowen and Gillingham (2004) show that the amphibians and reptile species that inhabit the islands of the Lake Michigan Archipelago are especially interesting.

Prior to their 2004 paper, Placyk and Gillingham (2002) had summarized the literature on the herpetofauna of the northern part of the Lake Michigan Archipelago, which they termed the “Beaver Archipelago.” The Lake Michigan Archipelago lies in eastern Lake Michigan, its southernmost islands adjacent to the Leelanau Peninsula and its northernmost to the Straits of Mackinac. This archipelago stretches north to south over about 90 km (55.8 mi.) and is composed of twelve major islands (see table 6) and several smaller ones. The highest islands (Beaver, High, South Fox, and North and South Manitou) were present about 9 to 10 ka BP. From about 4 to 8 ka BP, water levels were lower, and the northern islands Beaver, Garden, High, Hog, Squaw, Trout, and Whiskey were not only exposed but connected to the mainland by way of Waugoshance Point. At the same time, the Manitou Islands were connected to the mainland by way of the Leelanau Peninsula. It is not known whether the Fox Islands were ever connected to mainland Michigan. Lake levels rose again between 3 and 4 ka BP, and all but the highest parts of Beaver, Garden, High, the Foxes, and the Manitous were covered by water. Water levels then fell to those of modern Michigan. Table 6. The twelve major islands of the Lake Michigan Archipelago Island

Surface Area (Acres)

Distance to Lower Peninsula (Miles)

Beaver

37,401

17.4

Garden

4,917

18.0

Gull

269

33.6

High

3,694

26.0

Hog

2,530

13.0

895

22.4

North Fox North Manitou

1,306

6.2

South Fox

3,393

16.2

South Manitou

5,033

6.2

77

24.2

Trout

116

28.0

Whiskey

128

24.9

Squaw

Source: Modified from Bowen and Gillingham 2004.

Vertebrates from the mainland probably reached the islands by means of the land bridges 4 to 8 ka BP or by rafting across the lake after that interval (Hatt et al. 1948). It is believed that these land vertebrates came

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mainly from the Lower Peninsula. Bowen and Gillingham (2004) reported a total of eleven amphibian and ten reptile species from the islands of the Lake Michigan Archipelago. The distribution of these amphibians and reptiles on these islands is summarized in table 7. Table 7. Distribution of amphibian and reptile species on the Lake Michigan Archipelago Species

Island

Notophthalmus viridescens

Beaver, Garden, High, S. Manitou

Plethodon cinereus

Beaver, Garden, High, N. Fox, N. Manitou, S. Fox, S. Manitou, Squaw

Ambystoma laterale

Beaver, Garden, High, Trout

Ambystoma maculatum

Beaver, N. Manitou, S. Manitou

Bufo americanus

Beaver, Garden, High, Hog, N. Fox, N. Manitou, S. Fox, S. Manitou, Squaw, Trout, Whiskey

Hyla versicolor

Beaver, Trout

Pseudacris crucifer

Beaver, Garden, Gull, N. Fox, N. Manitou, S. Manitou, Trout

Rana catesbeiana

Beaver, N. Manitou

Rana clamitans

Beaver, Garden, High, N. Manitou

Rana sylvatica

Beaver, N. Manitou

Rana pipiens

Beaver, Garden, S. Manitou

Chelydra serpentina

Beaver, Garden, N. Manitou, S. Manitou

Chrysemys picta

Beaver, Garden, High, N. Manitou, S. Manitou

Thamnophis sirtalis

Beaver, Garden, High, N. Fox, N. Manitou, S. Fox, S. Manitou, Squaw, Trout, Whiskey

Thamnophis sauritus

Beaver, N. Manitou

Nerodia sipedon

Beaver, Garden, High, Hog, N. Fox, Squaw, Whiskey

Storeria dekayi

N. Manitou, S. Fox, S. Manitou

Storeria occipitomaculata

Beaver, Garden, High, Squaw, Whiskey

Diadophis punctatus

Beaver, Garden, N. Fox, N. Manitou, S. Fox, S. Manitou

Opheodrys vernalis

Beaver

Lampropeltis triangulum

Beaver, Garden, High, N. Fox, Whiskey

Source: Modified from Bowen and Gillingham 2004.

Bowen and Gillingham found that the larger islands supported relatively more herpetological species (both amphibians and reptiles) than the smaller ones. This is not surprising. But they also found that the distance between the islands and the mainland had no significant bearing on the number of amphibians or reptiles on these islands. The reason may be that all of these islands originated as land bridges (Hecner et al. 2002). The Lake

250

Michigan Archipelago has a less diverse herpetofauna than other archipelagos in the Great Lakes, according to Bowen and Gillingham (2004). As an example, they point out that the ratio of amphibian to reptile species is 16:19 in the Lake Erie Archipelago, 14:19 in the Georgian Bay Archipelago, and 15:6 in the Apostle Island Archipelago. The reason for these numbers is still speculative, but some suggestions have been made, such as (1) the comparatively fewer islands in the Lake Michigan Archipelago offered fewer targets for immigrants, (2) unrecorded extirpations may have occurred, and (3) censuses may have been incomplete. Further studies may suggest that a co-occurrence of events will explain the situation, a type of multiple working hypotheses that T. C. Chamberlain, an eminent Canadian geologist of the late nineteenth century, might have developed to explain why comparatively fewer number of species live on the Lake Michigan Archipelago. One certainty about the twenty-one total amphibian and reptile species recorded on the Lake Michigan Archipelago is that every one of these animals is a primary reinvading species (see table 3) (Holman 1992). Being primary would indicate to me that they are a hardy lot of animals that are able to adapt quickly to a variety of climates and habitats, which I assume would have helped in the colonization of big chunks of emergent rocks and sand in the “big lake.”

“Emmet Island” Right about at Harbor Springs on the north shore of Little Traverse Bay, the Transition Zone ends (see fig. 8) and the Canadian Biotic Province begins. A traveler is then in the true “north woods.” Emmet County is the most northwestern county in the Lower Peninsula of Michigan and forms at once the northernmost and most prominent of the series of western bulges of the mainland into Lake Michigan. During the Pleistocene Ice Age, Emmet County was cut off from the mainland by a wide channel and was cut off again, probably for the last time, about 4 ka BP during the so-called Nipissing Postglacial Lake Stage (Dorr and Eschman 1970). By the Algoma Postglacial Lake Stage, about 3 ka BP, much of Emmet County was rejoined to the mainland. In the summers shortly before and after World War II, I visited Lake Paradise (although at that time it was called Carp Lake because historic Indian peoples called

3. Quaternary Remains of Michigan Amphibians and Reptiles

white suckers “carp”) in Emmet County many times, and I saw the largest Eastern American Toads (Bufo americanus americanus) I have ever seen. Several of them were more than four inches long, and one old male that lived around our cottage woodpile was as big as an average Cane Toad (Bufo marinus) that I would later see in Mexico. Several journal articles have been written about the giant toads on various Lake Michigan islands, both on the Wisconsin and Michigan side of the lake (e.g., Long 1982, 1993; Gillingham 1988; Placyk and Gillingham

2002). It seems that some of the factors responsible for the giant size of the herpetofauna on extant Michigan Islands might have been operating on “Emmet Island” during the times this piece of land was cut off from the mainland. I have also noticed that Eastern Gartersnakes (Thamnophis sirtalis sirtalis) in Emmet County, especially those near the Michigan coast, all appear to be very distinctly colored, with an especially vivid black background and brilliant yellow stripes. I have often wondered if this was an “island effect.”

251

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275

General Index Note: Italicized page numbers indicate figures and tables. African elephants, role in ecosystem, 6 Algoma Postglacial Lake Stage, 250 American Toads, 18, 68, 68–73, 216, 216, 219, 223–24, 242–43, 250 amphibians and reptiles in Michigan: overview, 29–30; checklist, 27–29 Ann Arbor, Michigan, 22 annuli (growth rings), 129, 130–31 Apostle Island Archipelago, 250 Appalachian region, North America, 30, 51 archaeological sites in Michigan, 223–35, 242–45 aspen forest, 12, 12 Australia, Pleistocene epoch, 238 Baker, Rollin H., 19 Beal-Steere, Joseph, 18 Beaver Archipelago, 249 Beaver Island, 20 beaver ponds, 15 bedrock, in Michigan, 1–3, 2 (map), 10 beech-maple assemblage, 11 Bernabo, J. C., 7 biological stations and preserves, 19 biotic provinces, 8, 9 (map) birds, parenting by, 238 Blanding’s Turtle, 20, 121, 121–25, 221–22, 229–31, 242, 244, 244–45 bogs, defined, 15–16 Borneman, David, 22 Bowker, Richard, 20 Box Turtles, 135, 135–40, 232–33, 244–45 British Isles, native species, 17 Brownsnakes, 157, 191, 191–94, 248

C-14 (carbon-14), in radiocarbon dating, 214 “Cabinet of Natural History,” 18 Cambrian period, 211 Canadian Biotic Province, 8 Carolinian Biotic Province, 8 Carr, Archie, 9 Central Michigan University Biological Station, Beaver Island, 20 Cherry Tree substage, Kalsaka County, 5 classification of herpetological species, 22 climate: Holocene epoch, 5–8, 219; of MRLE regions, 9–10; Painted Turtles as indicators of summer, 218; Pleistocene epoch, 237–38 Clinton County, Lake Ovic, 14 Coldwater River drainage system, 10 collagen, in radiocarbon dating, 215 collection and identification of herpetological species, 22–25, 214 color vision, in Eastern Musk Turtle, 144 commensals, 238 Congdon, Justin D., 20 Cooperative Extension Service, Michigan State University, 20 Cordilleran Ice Sheet, 236 Crayfish Snake, 189 Creaser, Charles W., 20 Cretaceous period, 211 cultural periods: archaeological sequence of, 223; record of amphibians and reptiles, 211, 242, 242–45, 244 death-feigning, 165, 167, 193 Detroit Zoological Park, 21–22 Division of Natural Science, Michigan State University, 18–19 drumlins, 4

277

The Amphibians and Reptiles of Michigan

dystrophic lakes, 15 Early Woodland cultural period, 242 Emmet County ("Emmet Island"), 250–51 Endangered species: overview, 22; Copper-bellied Watersnake, 173; Eastern Box Turtle, 139; Eastern Spiny Softshell turtle, 149; Kirtland's Snake, 158; Small-mouthed Salamander, 46 England, loss of diversity in flora and fauna, 17 Eocene epoch, 211 E. S. George Reserve, 20 eskers, 4 eutrophic lakes, 14 extinctions during North American Pleistocene, 237 fens (alkaline bogs), 16 field guides to Michigan amphibians and reptiles, 20 fires, 7 Fisheries Division, MDNR, 22 forests, 7, 10, 10–13, 11–12 fossil remains: dating, 214–15; diagnostic skeletal elements, frogs and toads, 219; digging, 212–14, 214; Holocene epoch, 214, 242–43; Late Wisconsinan glacial stage, 217, 239, 239; Michigan and Great Lakes region, 212; nature of, 212–13; Pleistocene epoch, 112, 212–13, 215, 242–43; tools for collecting, 214. See also names of individual species fossil sites. See Site Index Four-toed Salamanders, 52, 52–54 Foxsnakes, 183–86, 184, 186, 186–88, 235, 240, 245 frog hunting, 89 frogs, in general: atlas and sacral vertebra, 24; as bait, 96; fossil remains, 213; generalized skeleton, dorsal view, 23; pedicellate teeth, 30; red-leg disease, 97 frog species and subspecies: American Bullfrog, 23, 87, 87–90, 224, 240, 243; Bird-voiced Treefrog, 80; Blanchard's Cricket Frog, 75, 75–77; Boreal Chorus Frog, 84, 245; Cope’s Gray Treefrog, 77–80; Gray Treefrog, 77–81, 79; Green Frog, 70, 77, 212, 216–17, 240; Mink Frog, 93, 99, 99–101, 245; Northern Green Frog, 70, 77, 90–93, 91, 100, 216–17; Northern Leopard Frog, 87, 94, 95, 95–99, 240; Northern Spring Peeper, 81–84, 82; Pickerel Frog, 87, 93–95, 94; Spring Peeper, 86, 219–20, 242; True Frog, 224–25; Western Chorus Frog, 84–87, 85; Wood Frog, 101, 101–4, 240

278

Gaige, Helen T., 18 gape-and-suck feeding behavior, Blanding's Turtle, 124 Gartersnake, 25, 157, 197, 197–99, 201–5, 202, 235–36, 240, 248, 250 geological history, Michigan: bedrock distribution, 1, 2 (map); Great Lakes region, 1–3, 3 (map), 4; landforms, 4; recent vegetational changes, 7–8; rocks, common, 2; surface formations, generalized, 5 (map) Geologic time scale, 1 Georgian Bay Archipelago, 250 gigantism, in individuals, 69 Gillingham, James C., 20 glacial stages, 3, 3–5, 236–37 glycerol, 79 Grand River system, 16 grasslands, 13, 13 (map) Gratz, Ronald, 20 Graves, Brent, 20 Great Lakes region, 241; fossil amphibian remains, 212; geological history, 1–3, 3 (map), 4; Ice Age, 237; temperatures, 10 Greensnakes, 177–80, 178 growing seasons, MRLE regions, 10 growth rings (annuli), 129, 130–31 gynogenesis, 35 habitats, modern: aspen forest, 12, 12; beech-maple assemblage, 11; grasslands, 13; lakes and ponds, 13–15; marshes, swamps, bogs and fens, 15–16; mesic deciduous northern forest, 12; mesic deciduous southern forest, 11; oak forest, 11; pine forests, 12; rivers and streams, 16–17; urban, 17–18; wet coniferous-boreal forest, 12; wet deciduous forest, 10–11; wet deciduous riparian, 10; wetlands, 7, 15–16 Harding, James H., 19 Hartweg, Norman, 18 Harwick Pines, Crawford County, 12 Hensley, Marvin M., 19 herpetological recolonization, postglacial Michigan, 240, 240–42, 241, 241, 242, 246, 250 Herpetological Resource and Management, LLC (HRM), 21 herpetology, history and status in Michigan, 18–22 Herpetology of Michigan (Ruthven), 18

General Index

Higgins Lake, Roscommon and Crawford counties, 14 Hog-nosed Snakes, 165–68, 166, 168 Holocene epoch: climatic and vegetational history, 5–8, 6 (map), 219; dating problem, 215; duration of, 3; fossil remains from, 214, 242–43; fossil sites, 212 (See also Site Index); herpetofauna documented in Michigan, 211, 219–22, 241–43 homing ability: Box Turtles, 137; Mudpuppies, 60–61; Musk Turtles, 144; Painted Turtles, 114; Spotted Turtles, 119; Watersnakes, 175; Wood Turtles, 127 Houghton Lake, Roscommon County, 14 human overkill hypothesis, in Pleistocene extinctions, 238 human uses of amphibians and reptiles, 22, 60, 96, 98, 110, 222–23, 225, 243–45, 244, 247 Hypsithermal interval, 7, 219 Ice Age, 3, 3–5, 236–37 ice sheets, 3 (map), 3–4, 4, 8, 215, 236, 241 identification of herpetological species, 22–25, 214 igneous rocks, in Michigan, 1, 2 Illinoian glacial stage, 236 Illinoian ice sheet, 3, 3 (map) indicator species, 58 interglacial ages, 3, 3, 236 interstadials, 3, 237 invader species, postglacial Michigan, 240, 240–41, 241, 241, 242, 246, 250 Jurassic period, 211 Kalamazoo Nature Center, 21 Kalsaka County, Cherry Tree substage, 5 kames, 4 KBS (W. K. Kellogg Biological Station), Michigan State University, 20 Kent County, Middle Woodland site, 244 kettle holes, 4 Kilby, John, 243 Kingsnakes, 161, 168–71, 248 Kirtland's Snake, 155–58, 156, 246–47 Kluge, Arnold G., 18 Lake Erie Archipelago, 250 Lake Michigan Archipelago, 249, 249, 250 Lake Ovic, Clinton Count, 14

lake plains, 4 lakes and ponds, 13–15 Late Archaic cultural period, 242 Late Devonian period, 211 Late Pleistocene, 211–12, 241 Late Woodland cultural period, 242, 242–43 Laurentide Ice Sheet, 236, 241 leatherleaf bog, southeastern Grand Traverse County, 16 Lissamphibia, 30 Lithobates spp., 87 Little Ice Age, 7, 219 lizards, in general: fossil remains, 25, 213; identification of, 24; salamanders compared to, 30 lizard species and subspecies: Eastern Six-lined Racerunner, 153; Five-lined Skink, 150–53, 151; Giant Monitor Lizard, 238; Prairie Racerunner, 153; Sand Lizard, 17; Six-lined Racerunner, 153, 153–55, 246–47; Texas Yellow-headed Racerunner, 153 logging, exploitive, 7 Lower Peninsula, 16, 215 Lungless Salamanders, 51–61 maceration process, 23 macroteiids, 151 mammals, large, 5–6 mammals, parenting by, 238 mammoths, 5–6, 212 Manistee River, Kalkaska County, 16 Manistique River system, 16 Map Turtles, 128, 131–35, 132, 213, 222, 231–32, 239, 244, 248–49 Marbled Salamanders, 40–43, 41 marshes, 15, 16, 16 Mason-Quimby (MQ) Line, 8–9, 9 (map), 212, 241 Massasaugas, 155, 185, 205–9, 206, 206 mastodonts, 5–6, 212, 217 MDNR (Michigan Department of Natural Resources), 21–22 Menominee River system, 16 mesic deciduous northern forest, 12 mesic deciduous southern forest, 11 metamorphic rocks, in Michigan, 1, 2 Michigan: counties and islands, 1 (map); regional divisions, 8–10, 8 (map) (See also Michigan Regional Landscape Ecosystems [MRLE])

279

The Amphibians and Reptiles of Michigan

Michigan Academician (journal), 21 Michigan Academy of Science, Arts, and Letters (MASAL), 21 Michigan Department of Conservation (MDC), 21 Michigan Department of Natural Resources (MDNR), 21–22 Michigan Fishing Guide (MDNR), 22 Michigan Frog and Toad Survey (MFTS), 21 Michigan Herp Atlas Project, xiv, 21 Michigan Natural Features Inventory (MNFI), 7, 20, 21 Michigan Regional Landscape Ecosystems (MRLE), 9 (map); overview, 27, 245; characteristics, regional, 9–10; physiographic features, 9–11; relict species, 246–49; rivers and streams, 14, 16; species diversity, 245–46 Michigan State University, 18–20 microteiids, 151 Middle Archaic cultural period, 242 Middle Woodland cultural period, 242, 244, 244–45 Mifsud, David A., 22 migration facilitation, 51 Milksnakes, 168–71, 169, 169 Miocene epoch, 211 mixed grassland and oak savanna, 13 (map) Mole Salamanders, 30–51 moraines, 4 MRLE. See Michigan Regional Landscape Ecosystems (MRLE) Mudpuppies, 58, 58–61, 59 Museum of Zoology, Division of Reptiles and Amphibians, 18 Muskegon County, Plum Point substage, 5 muskegs, 16 musk oxen fossil remains, 212 Musk Turtles, 143–47, 144, 213, 221, 222, 233, 239, 242, 248 National Amphibian Conservation Center, 22 neoglaciation, 219 Newts, 18, 50, 62, 62–65 New World Pond Turtles: Blanding’s Turtle, 20, 121, 121–25, 221–22, 229–31, 242, 244, 244–45; Box Turtles, 135, 135–40, 232–33, 244–45; Map Turtles, 128, 131–35, 132, 213, 222, 231–32, 239, 244, 248–49; Painted Turtles, 111–17, 112, 213, 217, 217–18, 220–21, 221, 227–29, 239, 242–44;

280

Pond Sliders, 104, 111, 114, 140–43, 213, 233, 239, 244, 247; Softshell Turtles, 146–49, 147, 217, 218, 218–19, 222–23, 233–35, 244; Spotted Turtles, 117–21, 118, 221–22, 229, 242; Wood Turtles, 125–31, 126, 231 Nipissing Postglacial Lake Stage, 3, 250 Northern Bog Lemming, 219 northern mesic beech-maple forest, 12 northern oak-hickory assemblage, 11 Norton Mounds, Grand Rapids, 223 Nussbaum, Ronald A., 18 oak forest, 11 oak savannas, 13, 13 (map) Oligocene epoch, 211 oligotrophic lakes, 14 Ovchynnyk, Michael, 19 Painted Turtles, 111–17, 112, 213, 217, 217–18, 220–21, 221, 227–29, 239, 242–44 Palocene epoch, 211 parenting, in birds and mammals, 238 pine forests, 7, 12 Pipe Creek Sinkhole biota, Early Pliocene, 236 plaid hypothesis, 237 plant communities, reestablishment in previously glaciated regions, 5 Pleistocene epoch: in Australia, 238; in British Isles, 17; climate fluctuations, 237–38; climatic and vegetational history, 5–8, 6 (map); extinctions during, 237; fossil criteria, 215; fossil remains from, 112, 212–13, 215–18, 242–43; glacial activity, 236–37; great lakes, ancient, 212; herpetofauna of, 215–18, 236–39; herpetological sites, 211–12, 241 (See also Site Index); Ice Age, 3–5; postglacial vertebrate records, 8; reinvasion patterns, as analogs for the future, 240; sediments, 1; vegetation of Twocreekan substage, 216 plinkers, 134 Pliocene epoch, 211, 236 Plum Point interstadial, 3, 5, 237 Pond Sliders, 104, 111, 114, 140–43, 213, 233, 239, 244, 247 Port Talbot interstadial, 3 postglacial herpetological reentrants, 238, 240, 240–41, 241, 241, 242, 246, 250

General Index

prairies, 13 primary invaders, postglacial Michigan, 240, 241, 246, 250 Quaternary period, 211–12 Queen Snakes, 188–91, 189, 248 Racers, 138, 158–62, 159, 248 Racerunners, 153, 153–55, 246–47 radiocarbon dating (carbon-14 method), 214–15 Rancho La Brea, California, commensal birds and dung beetles, 238 range extensions of reptile species, 249–50 Ratsnakes, 180–83, 181 Red-backed Salamanders, 51, 54–58, 55–56 Red-bellied Snakes, 194–96, 195, 195–96 relict species, 246–49 reptiles: before and after the Ice Age, 236; from archaeological sites in Michigan, 225–35; from the Holocene of Michigan, 220–23. See also amphibians and reptiles; individual species Ribbonsnakes, 44, 199–201 Ring-necked Snakes, 57, 162, 162–65 rivers, major categories, 14–15 rivers and streams, as habitat type, 16–17 Rowe, John, 20 Ruthven, Alexander G., 18 Sager, Abram, 18 Saginaw River system, 16 salamanders, in general: in Appalachian region of North America, 30, 51; compared to lizards and frogs, 30; humeri and mandibles, 24; hybrid, 34–35; identification of, 24; pedicellate teeth of, 30; polypoids, 34–35; skeleton, generalized, 24; triploids compared to diploids, 34; vertebrae, 24, 212 salamander species and subspecies: Blue-spotted/ Jefferson complex, 24, 34–35; Blue-spotted Salamander, 31, 31–34, 37; Broken-striped Newt, 50, 64; Central Newt, 62, 64; Common Mudpuppy, 58, 58–61, 59; Common Newt, 18; Eastern Newt, 62, 62–65; Eastern Red-backed Salamander, 51, 54– 58, 55–56; Eastern Tiger Salamander, 46, 46–51, 47; Four-toed Salamander, 52, 52–54; Jefferson Salamander, 34, 38; Marbled Salamander, 40–43, 41; Red-spotted Newt, 62, 64; Silvery Salamander,

35; Small-mouthed Salamander, 43, 43–46; Spotted Salamander, 34, 36–40; Streamside Salamander, 35; Tiger Salamander, 34, 50–51; Tremblay's Salamander, 35; Western Lesser Siren, 65, 65–67, 246–47 Sargent, Lori, 21 savannas, 13 Schneider, Greg, 19 scientific names of amphibians and reptiles, 27 sea levels, Ice Age, 237 secondary invaders, postglacial Michigan, 241, 241, 246 sedimentary rocks, common in Michigan, 1, 2 Sexton, Owen J., 20 sibling species, defined, 77 Sirens, 65, 65–67, 246–47 skeletal specimens, assembly of, 23 Skink, 150–53 Skinks, 151 slow stream, Grand Taverse County, 17 Small-mouthed Salamanders, 43, 43–46 Smith, William H., 18 Smooth Snakes, 17 snakes, in general: colubrid snake, typical, 214; fossil remains, 213; identification of, 24–25; vertebral column regions, 25 snake species and subspecies: Black Hills Red-bellied Snake, 194; Black Ratsnake (See Central Ratsnake); Blotched Watersnake, 172; Blue Racer, 158–62, 159, 248; Blue-striped Ribbonsnake, 200; Butler’s Gartersnake, 197, 197–99, 248; Carolina Watersnake, 174; Central Ratsnake, 180–83, 181; Chicken Snake (See Central Ratsnake); Common Kingsnake, 161; Common Ribbonsnake, 199–200; Common Watersnake, 33, 172, 174, 174–77; Copper-bellied Watersnake, 171–73, 172, 246–48; Cow Snake (See Central Ratsnake); DeKay's Brownsnake, 157, 191, 191–94; Dusty Hog-nosed Snake, 165; Eastern Foxsnake, 183–86, 184, 235; Eastern Gartersnake, 25, 201–5, 202, 250; Eastern Hog-nosed Snake, 165–68, 166; Eastern Milksnake, 168–71, 169; Florida Red-bellied Snake, 194; Gartersnake, 157, 202–3, 205, 235–36, 240; Glossy Crayfish Snake, 189; Graham's Crayfish Snake, 189; Kirtland's Snake, 155–58, 156, 246–47; Lake Erie Watersnake, 174; Midland Brownsnake, 191, 248; Midland Watersnake, 174; Mississippi Ring-necked

281

The Amphibians and Reptiles of Michigan

Snake, 163; North American Watersnake, 235; Northern Black Racer, 158–59; Northern Brownsnake, 191; Northern Red-bellied Snake, 194–96, 195; Northern Ribbonsnake, 44, 199– 201; Northern Ring-necked Snake, 162, 162–65; Peninsula Ribbonsnake, 200; Pilot Black Snake (See Central Ratsnake); Pine Snake (See Western Foxsnake); Plains Gartersnake, 197; Prairie Ringnecked Snake, 163; Puff Adder (See Eastern Hog-nosed Snake); Queen Snake, 188–91, 189, 248; Racer, 138; Red-bellied Watersnake, 172; Red Milksnake, 169; Ribbonsnake, 200–201; Ring-necked Snake, 57, 164; San Francisco Gartersnake, 204; Scarlet Kingsnake, 169; Short-headed Gartersnake, 197; Smooth Earthsnake, 39; Smooth Greensnake, 177–80, 178; Smooth Snake, 17; Southern Black Racer, 158–59; Southern Hog-nosed Snake, 165; Southern Ring-necked Snake, 163; Striped Crayfish Snake, 189; Texas Brownsnake, 191; Texas Ratsnake, 181–82; Water Moccasin, 176; Western Foxsnake, 183–84, 186, 186–88, 245; Western Hog-nosed Snake, 165, 168; Wonambi, 238; Yellow-bellied Watersnake, 171–72 Snapping Turtles, 104, 105, 105–11, 220–21, 225–27, 239, 243–44 Softshell Turtles, 146–49, 147, 217, 218, 218–19, 222–23, 233–35, 244 southern oak-hickory assemblage, 11 species diversity, 245–46 Species of Greatest Conservation Need: Blue-spotted Salamander, 34; Common Mudpuppy, 61; Eastern Tiger Salamander, 51; Four-toed Salamander, 54; Fowler's Toad, 74–75; Northern Leopard Frog, 98; Pickerel Frog, 95; Spotted Salamander, 39 Species of Special Concern: overview, 22; Blanding's Turtle, 125; Central Ratsnake, 183; Eastern Massasauga, 209; Queen Snake, 189; Six-lined Racerunner, 154; Western Lesser Siren, 67; Wood Turtle, 129 sperm storage by female Gartersnakes, 203 Spotted Salamanders, 31, 31–34, 36–40 Spotted Turtles, 117–21, 118, 221–22, 229, 242 starter populations, 238 swamps, bogs and fens, 15–16 taxonomic placement of amphibians and reptiles, 27 Tegus, 153, 153–55, 246–47

282

temperature-dependent sex determination (TSD) in turtles, 107, 115, 123, 138, 142 tertiary invaders, postglacial Michigan, 241, 242, 246 Test, Frederick H., 19 tetrapods (four-legged vertebrates), 211 Texas Brownsnake, 191 Thompson, Crystal, 18 Threatened species: overview, 22; Blanchard's Cricket Frog, 77; Eastern Foxsnake, 185; Marbled Salamander, 44; Spotted Turtle, 120 Tiger Salamanders, 34, 46, 46–51, 47, 50–51 Tinkle, Donald W., 18, 20 toad species and subspecies: American Toad, 18, 216, 216, 219, 223–24, 242–43; Cane Toad, 67; Dwarf American Toad, 69; Eastern American Toad, 68, 68–72, 72–73, 216, 250; Fowler's Toad, 68, 70–75, 72, 74; Natterjack Toad, 17; Southern Toad, 70 tools for collecting vertebrate fossils, 214 Transition Zone, 250 Treefrogs, 75, 75–81, 79, 81–84, 82, 84–87, 85, 219–20, 242, 245 Triassic period, 211 Trowbridge, William P., 18 True Frogs, 23, 70, 77, 87, 87–93, 91, 94, 95, 95–99, 99, 99–101, 101, 101–4, 212, 216–17, 224–25, 240, 243, 245 True Toads, 17–18, 67, 68, 68–75, 72, 74, 216, 216, 219, 223–24, 242–43, 250 turtles, in general: abundance in archaeological sites in Michigan, 243; diagnostic bones, 239; emydid shell and bones, 25; fossil remains, 213; human uses of, 244, 244–45; identification of, 24; Pleistocene remains, 216–17 turtle species and subspecies: Alligator Snapping Turtle, 104; Blanding’s Turtle, 20, 121, 121–25, 221–22, 229–31, 242, 244, 244–45; Bog Turtle, 111, 125; Eastern Box Turtle, 135, 135–40, 232–33, 244–45; Eastern Musk Turtle, 143–47, 144, 213, 221, 222, 233, 239, 242, 248; Eastern Painted Turtle, 112–13; Eastern Snapping Turtle, 105, 105–11, 220–21, 225–27; Eastern Spiny Softshell, 147, 147–49; European Pond Turtle, 111, 140, 142, 218; Florida Snapping Turtle, 105; Gray's Slider, 111; Midland Painted Turtle, 112, 112–16; Northern Map Turtle, 128, 131–35, 132, 231–32, 244, 248–49; Painted Turtle, 111–17,

General Index

213, 217, 217–18, 220–21, 221, 227–29, 239, 242–44; Pond Slider, 104, 114, 140, 213, 233, 239; Red-eared Slider, 140, 140–43, 244, 247; Sculptured Turtles, 125; softshell turtles, 146–49, 217, 218–19, 222–23, 233–35, 244; Southern Painted Turtle, 112–13; Spiny Softshell, 217, 218, 218–19, 222–23, 233–35; Spotted Turtle, 117–21, 118, 221–22, 229, 242; Three-toed Box Turtle, 137; Western Painted Turtle, 112; Wood Turtle, 125–31, 126, 231 Twocreekan substage vegetation, 216 University of Michigan, 18–19 Upper Peninsula (UP), 8, 16 urban habitat, 17–18 “Variations and Genetic Relationships of the Garter- Snakes” (Ruthven), 18 vegetation: effect of Pleistocene ice advances and retreats, 215, 237; forest cover types, 10–13, 12; in Pleistocene and Holocene epochs, 5–8, 6 (map); presettlement, 13; reestablishment in previously glaciated regions, 5; in regional landscape ecosystems, 9–10; Twocreekan substage, 216. See also habitats, modern vernal ponds, 15 vertebrate fossils, 8, 212, 212. See also fossil remains vertebrate fossils, tools for collecting, 214 vertebrate paleontologists, 23 viper species and subspecies: Desert Massasauga, 206; Eastern Massasauga, 155, 185, 205–9, 206; Western Massasauga, 206

Walker, Charles F., 18 Watersnakes, 33, 171–73, 172, 172, 174, 174–77, 235, 246–48 Weatherby, Craig, 20 wet coniferous-boreal forest, 12, 12 wet deciduous forest, 10–11 wet deciduous riparian habitat, 10 wetlands, 7, 12, 15–16 Wilbur, Henry M., 20 Wildlife Division, MDNR, 21–22 Williams, Joseph R., 19 Wintergreen Lake, Barry County, 215 Wisconsinan glacial stage, 3, 3 (map), 211–12, 213, 216, 217, 236–37, 239 W. K. Kellogg Biological Station (KBS), Michigan State University, 20 woodland ponds, temporary (vernal ponds), 15 Wood Turtles, 125–31, 126, 231 worm stomping, by Wood Turtles, 127 zooarchaeologists, 23, 222

283

Taxonomic Index Note: Italicized page numbers indicate figures and tables. Acris crepitans blanchardi, 75, 75–77 Agkistrodon mokasen, 176 Ambystoma, 211; barbouri, 35, 44; jeffersonianum, 34, 38; laterale, 31, 31–34, 37; laterale x jeffersonianum, 34–35; maculatum, 34, 36, 36–40; opacum, 40–43, 41, 246–48; platineum, 35; texanum, 43–46, 247; tigrinum, 34, 50–51, 248; tigrinum melanstictum, 50; tigrinum tigrinum, 46, 46–51, 47, 248; tremblayi, 35 Ambystomatidae, 30–51 Anaxyrus, 68 Anura, 30, 67–104, 215–20, 223–25 Apalone, 211, 244; spinifera, 217, 218, 218–19, 222–23, 233–35; spinifera spinifera, 147, 147–49, 248 Aspidoscelis: sexlineata, 153, 153–55, 246–47; sexlineata sexlineata, 153; sexlineata stephensae, 153; sexlineata viridis, 153 Bufo, 211; americanus, 18, 216, 216, 219, 223–24, 242– 43; americanus alani, 69; americanus americanus, 68, 68–71, 72–73, 216, 250; americanus charlesmithi, 69; calamita, 17; fowleri, 68, 70–75, 72, 74; terrestris, 70 Bufonidae, 17, 67–75, 216, 219, 223–24, 242–43, 250 Caudata, 30–67 Chelydra, 211, 243–44; serpentina, 213; serpentina osceola, 105; serpentina serpentina, 105, 105–11, 220–21, 225–27 Chelydridae, 104–11, 220–21, 225–27, 239, 243–44 Chrysemys, 211; picta, 111–17, 213, 217, 217–18, 220–21, 221, 227–29, 239, 242–44; picta bellii, 112–13; picta dorsalis, 112–13; picta marginata, 112, 112–16; picta picta, 112 Claudius, 143

Clemmys: guttata, 117–21, 118, 221–22, 229, 242; insculpta (See Glyptemys insculpta) Clonophis kirtlandii, 155–58, 156, 246–47 Cnemidophorus sexlineatus. See Aspidoscelis sexlineata Coluber, 211; constrictor, 138; constrictor constrictor, 158–59; constrictor flaviventris, 158; constrictor foxii, 158–62, 159, 248; constrictor priapus, 158–59 Colubridae, 155–205, 235–36 Conraua goliath, 87 Coronella austriaca, 17 Crotalinae, 205 Diadophis, 211; punctatus, 57, 164; punctatus arnyi, 163; punctatus edwardsii, 162, 162–65; punctatus punctatus, 163; punctatus stictogenys, 163 Elaphe obsoleta obsoleta. See Pantherophis spiloides Elaphe vulpina gloydi. See Pantherophis gloydi Emydidae, 25, 111–42, 217–18, 220–22, 227–33 Emydoidea, 211; blandingii, 20, 121, 121–25, 213, 221–22, 229–31, 239, 242, 244, 244–45 Emys orbicularis, 111, 140, 142, 218 Glyptemys: insculpta, 125–31, 126, 231; muhlenbergii, 111, 125 Graptemys, 213, 222, 239; geographica, 128, 131–35, 132, 231–32, 244, 248–49; ouachitensis, 134; pseudogeographica, 134 Gymnophiona, 30 Hemidactylium scutatum, 52, 52–54 Heterodon, 211; gloydi, 165; nasicus, 165, 168; platirhinos, 165–68, 166; simus, 165 Hseperotestudo, 238 Hydromantes, 51

285

The Amphibians and Reptiles of Michigan

Hyla, 75, 211; avivoca, 80; chrysoscelis, 77–80; versicolor, 77–81, 79 Hylidae, 75–86, 219–20 Kinosternidae, 142–46, 222, 233 Kinosternon flavescens, 213 Lacerta agilis, 17 Lampropeltis, 211; getula, 161; pyromelana, 214; triangulum, 169–70, 248; triangulum elapsoides, 169; triangulum syspila, 169; triangulum triangulum, 168–71, 169 Lissamphibia, 30 Lithobates sp., 87 Macrochelys, 104 Necturus, 211; maculosus maculosus, 58, 58–61, 59; maculosus stictus, 59 Nerodia, 211, 235; erythrogaster erythrogaster , 172; erythrogaster flavigaster , 171–72; erythrogaster neglecta, 171–73, 172, 246–48; erythrogaster transversa, 172; sipedon insularum, 174; sipedon pleuralis, 174; sipedon sipedon, 33, 172, 174, 174–77; sipedon williamengelsi, 174 Notophthalmus, 61; viridescens, 62, 62–65; viridescens dorsalis, 50, 64; viridescens louisianensis, 62, 64; viridescens viridescens, 62, 64 Opheodrys vernalis, 177–80, 178 Pantherophis, 211, 240; gloydi, 183–86, 184, 235; kansensis, 188; spiloides, 180–83, 181; vulpinus, 183–84, 186, 186–88, 245 Plestiodon, 211; fasciatus, 150–53, 151 Plethodon, 211; cinereus, 51, 54–58, 55–56 Plethodontidae, 52–58 Proteidae, 58–61 Proteus anguinus, 58 Pseudacris: crucifer, 86, 219–20, 242; crucifer bartramiana, 83; crucifer crucifer, 81–84, 82; maculata, 84, 245; triseriata, 84–87, 85 Pseudemys scripta, 243 Pseudobranchus, 64

286

Rana, 224–25; catesbeiana, 23, 87, 87–90, 224, 240, 243; clamitans, 70, 77, 212, 216–17, 240; clamitans clamitans, 90; clamitans melanota, 70, 77, 90–93, 91, 100, 216–17; palustris, 87, 93–95, 94; pipiens, 87, 94, 95, 95–99, 240; septentrionalis, 93, 99–101, 245; sylvatica, 101, 101–4, 240 Ranidae, 87–104, 212, 216–17, 224–25 Regina: alleni, 189; grahamii, 189; ridgida, 189; septemvittata, 188–91, 189, 248 Rhyacosiredon, 30 Salamandridae, 61–64 Scincidae, 150–55, 246–47 Siren: intermedia, 65, 65–67; intermedia intermedia, 67; intermedia nettingi, 65, 65–67, 246–47; lacertina, 64, 67 Sirenidae, 64–67 Sistrurus: catenatus, 205–6; catenatus catenatus, 155, 185, 205–9, 206; catenatus edwardsii, 206; catenatus tergeminus, 206 Sorex cinerus, 54 Squamata, 149–209, 235–36 Staurotypus, 143 Sternotherus, 211; odoratus, 143–47, 144, 213, 221, 222, 233, 239, 242, 248 Storeria: dekayi, 157, 191, 191–94; dekayi dekayi, 191; dekayi texana, 191; dekayi wrightorum, 191, 248; occipitomaculata, 195–96; occipitomaculata obscura, 194; occipitomaculata occipitomaculata, 194–96, 195; occipitomaculata pahasapae, 194 Synaptomys cf. Synaptomys borealis, 219 Taricha, 61 Teiidae, 153–54 Terrapene: carolina bauri, 136; carolina canaliculata, 136; carolina carolina, 135, 135–40, 232–33, 244–45; carolina major, 136; carolina triunguis, 137; ornata, 213 Testudines, 104–49, 217–18, 220–22, 225–35 Thamnophis: brachystoma, 197; butleri, 197, 197–99, 248; radix, 197; sauritus, 200–201; sauritus nitae, 200; sauritus sackenii, 200; sauritus sauritus, 199–200; sauritus septentrionalis, 44, 199–201; sirtalis, 157, 202–3, 205, 235–36, 240; sirtalis infernalis, 204; sirtalis sirtalis, 25, 201–5, 202, 250 Trachemus venusta grayi, 111

Taxonomic Index

Trachemys: scripta, 104, 114, 140, 213, 233, 239; scripta elegans, 140, 140–43, 244, 247; venusta grayi, 111 Trionychidae, 146–49, 218–19, 222–23, 233–35, 244 Triturus vulgaris, 18

Viperidae, 205–9 Virginia valeriae, 39

287

Site Index Note: Italicized page numbers indicate figures and tables. Aldrich Site (20GR221), Gratiot County: Emydoidea blandingii (Blanding’s Turtle), 230 Allegan County. See Allegan Dam Allegan Dam (20AE56), Allegan County: Apalone spinifera (Spiny Softshell), 234 Bay City (sites 20BY79 and 20BY77), Bay County: Chrysemys picta (Painted Turtle), 227 Bay County. See Bay City; Kantzler Site; Marquette Viaduct Site; Trombly House Bear Creek Site (20SA1043), Saginaw County: Apalone spinifera (Spiny Softshell), 233; Chelydra serpentina (Snapping Turtle), 225; Chrysemys picta (Painted Turtle), 227; Emydoidea blandingii (Blanding’s Turtle), 229; Pantherophis gloydi (Eastern Foxsnake), 235; Sternotherus odoratus (Eastern Musk Turtle), 233 Bridgeport Township Site (20SA620), Saginaw County: Emydoidea blandingii (Blanding’s Turtle), 230

Daviess County, Indiana. See Prairie Creek D Site Dolomitic Fissure 1 Site, Mackinac County, 242; Bufo americanus (American Toad), 219; Pseudacris crucifer (Spring Peeper), 219–20 Durst Archaeological Site, south-central Wisconsin: Trachemys scripta elegans (Red-eared Slider), 247 Elba Township Site (20LP98), Lapeer County: Rana catesbeiana (American Bullfrog), 224 Farmington Township, Oakland County: Chelydra serpentina serpentina, 220–21; Chrysemys picta, 221 Fenton Lake Locality, Genesee County: Apalone spinifera (Spiny Softshell), 222–23 Fissure I Site. See Dolomitic Fissure 1 Site, Mackinac County Foster Site (20SA74), Saginaw County: Apalone spinifera (Spiny Softshell), 234 Gratiot County. See Aldrich Site; Slavic Site

Carp River Site (FS-09–10–05–322), Mackinac County: Chelydra serpentina (Snapping Turtle), 226 Caseville Airport Site (20HU164), Huron County: Chrysemys picta (Painted Turtle), 228 Cassasa Site (20SA1021), Saginaw County: Apalone spinifera (Spiny Softshell), 234; Bufo americanus (American Toad), 223; Chelydra serpentina (Snapping Turtle), 226; Chrysemys picta (Painted Turtle), 228; Emydoidea blandingii (Blanding’s Turtle), 230; Rana catesbeiana (American Bullfrog), 224; Thamnophis sp. (North American Gartersnakes), 235–36 Charlevoix County. See O’Neil Site; Pine River Channel Site Christensen Bog Mastodont Site, Hancock County, Indiana, 239; diagnostic turtle bones from, 239

Harper Site, Shiawassee County, 241–42; Chrysemys picta (Painted Turtle), 220–21, 242; Clemmys guttata (Spotted Turtle), 221, 242; Emydoidea blandingii (Blanding's Turtle), 221–22, 242; mid-Holocene scene, 221; Sternotherus odoratus (Eastern Musk Turtle), 222 Heisler Mastodont Site, Calhoun County: Apalone spinifera (Spiny Softshell), 218–19 Hiawatha National Forest Site FS 09–10–01–328, Delta County: Chrysemys picta (Painted Turtle), 229, 244 Huron County. See Caseville Airport Site

289

The Amphibians and Reptiles of Michigan

Juntunen Site (20MK1), Bois Blanc Island, Mackinac County: Chelydra serpentina (Snapping Turtle), 226; Chrysemys picta (Painted Turtle), 228; Emydoidea blandingii (Blanding’s Turtle), 230; Glyptemys insculpta (Wood Turtle), 231; Terrapene carolina (Eastern Box Turtle), 232 Kantzler Site (20BY30), Bay County: Chelydra serpentina (Snapping Turtle), 226; Emydoidea blandingii (Blanding’s Turtle), 231 Kline 1 Site (20SJ29), St. Joseph County: Apalone spinifera (Spiny Softshell), 234; Sternotherus odoratus (Eastern Musk Turtle), 233 Mackinac County. See Carp River Site; Dolomitic Fissure 1 Site; Juntunen Site Marquette Viaduct Site (20BY28), Bay County: Apalone spinifera (Spiny Softshell), 234; Chelydra serpentina (Snapping Turtle), 226; Chrysemys picta (Painted Turtle), 227–28; Emydoidea blandingii (Blanding’s Turtle), 229 Meskill Road Water Well Site, St. Clair County, 241; Bufo americanus (American Toad), 216 Millington Township drainage ditch, Tuscola County: Chelydra serpentina serpentina (Eastern Snapping Turtle), 220 Moccasin Bluff (20BE8), Berrien County: Apalone spinifera (Spiny Softshell), 235; Chelydra serpentina (Snapping Turtle), 227; Emydoidea blandingii (Blanding’s Turtle), 231; Graptemys geographica (Northern Map Turtle), 232; Terrapene carolina (Eastern Box Turtle), 232 New Hudson Mastodont Site, Oakland County: Chrysemys picta (Painted Turtle), 217–18 Norton Mound Group, Kent County: Emydoidea blandingii (Blanding’s Turtle), 230, 244; Terrapene carolina (Eastern Box Turtle), 232 O’Neil Site (20CX18), Charlevoix County: Chrysemys picta (Painted Turtle), 228; Rana sp. (True Frog), 224 Pine River Channel Site (20CX19), Charlevoix County: Chrysemys picta (Painted Turtle), 228 Porter Creek South (20MN100), Manistee National Forest, Mason County: Chrysemys picta (Painted Turtle), 228–29

290

Prairie Creek D Site, Daviess County, Indiana, 238–39, 241; diagnostic turtle bones from, 239; Rana catesbeiana, 240 Ranger Walker I (200A180), Manistee National Forest, Oceana County: Emydoidea blandingii (Blanding’s Turtle), 230 Ranger Walker II (200A181), Manistee National Forest, Oceana County: Chrysemys picta (Painted Turtle), 229; Emydoidea blandingii (Blanding’s Turtle), 230 Rock Hearth Site (20BE306), Berrien County: Apalone spinifera (Spiny Softshell), 233, 233; Chelydra serpentina (Snapping Turtle), 225, 225; Chrysemys picta (Painted Turtle), 227, 244; Thamnophis sp. (North American Gartersnakes), 235 Saginaw County. See Bear Creek Site; Bridgeport Township Site; Cassasa Site; Foster Site; Schmidt Site; Schultz Site; Stadelmeyer Site; Vogelaar Site; Weber I Site Saginaw River mouth: Graptemys sp. (Specifically Undetermined Map Turtle), 222 Schmidt Site (205A192), Saginaw County: Apalone spinifera (Spiny Softshell), 233–34; Chelydra serpentina (Snapping Turtle), 225 Schultz Site (20SA2), Saginaw County, 244–45; Apalone spinifera (Spiny Softshell), 234; Chelydra serpentina (Snapping Turtle), 226; Chrysemys picta (Painted Turtle), 228; Clemmys guttata (Spotted Turtle), 229; Emydoidea blandingii (Blanding’s Turtle), 230, 244; Graptemys geographica (Northern Map Turtle), 231; Terrapene carolina (Eastern Box Turtle), 232; Thamnophis sp. (North American Gartersnakes), 235; Trachemys scripta (Pond Slider), 233, 243; Trachemys scripta elegans (Red-eared Slider), 244, 247 Shelton Mastodont Site, Oakland County, 216, 241; Rana clamitans (Green Frog), 216–17 Sheriden Pit Cave Site, Wyandot County, Ohio, 239, 241 Slavic Site (20GR221), Gratiot County: Bufo sp., 224; Emydoidea blandingii (Blanding’s Turtle), 230 Spring Creek Site (20MU3), Muskegon County: Chrysemys picta (Painted Turtle), 229; Terrapene carolina (Eastern Box Turtle), 232

Site Index

Stadelmeyer Site (20SA195), Saginaw County: Apalone spinifera (Spiny Softshell), 234; Chelydra serpentina (Snapping Turtle), 226; Emydoidea blandingii (Blanding’s Turtle), 231; Graptemys geographica (Northern Map Turtle), 231; Nerodia sp. (North American Watersnakes), 235; Rana sp. (True Frog), 224–25 Trombly House (20BY70), Bay County: Bufo americanus (American Toad), 224; Chelydra serpentina (Snapping Turtle), 227; Chrysemys picta (Painted Turtle), 229; Emydoidea blandingii (Blanding’s Turtle), 231

Weber I Site (20SA581), Saginaw County: Chelydra serpentina (Snapping Turtle), 225; Chrysemys picta (Painted Turtle), 227 Wymer West Knoll Site (20BE132), Berrien County: Apalone spinifera (Spiny Softshell), 235; Bufo sp. (Toad), 224; Chelydra serpentina (Snapping Turtle), 227; Chrysemys picta (Painted Turtle), 229; Graptemys geographica (Northern Map Turtle), 232; Rana sp. (True Frog), 225; Terrapene carolina (Eastern Box Turtle), 233

Vogelaar Site (205A291), Saginaw County: Chelydra serpentina (Snapping Turtle), 225

291